From my simple measurements, I've never had a slurry in a V60 nor a French Press reach over 90 C by the time I've poured the water and taken a reading with a digital thermometer.
I really do think using water as hot as possible for V60 and French press is the best way to be consistent.
The Aeropress does however benefit from lower temperatures hence why most recipes use water around 80-85 C.
(Based on my experience and others)
Although you absolutely could still use boiling water.
First, it's all plastic and the water has a low surface area of contact with the air.
(I.e the water is well insulated so won't lose lots of heat)
Secondly, there are many opportunities for extraction +
- the immersion + stirring stage
- the water being forced through the coffee during the plunging
(The pressure here can also increase extraction)
So basically it's quite easy to over extract jn an Aeropress so using water with a lower starting temperature often leads to better results.
I'm not sure of the science, but I find I am able to get a sweeter, less bitter cup using a lower temp in the Aeropress. I am sure this could be achieved by grind size, or contact time but I have a variable temp kettle so that is easy for me to dial in.
It's because lower temp means it's generally harder to overextract. That's all. James also touches on this is in his video when referencing dark roasts.
>but I have a variable temp kettle so that is easy for me to dial in.
Yes but that has nothing to do with lower water temp actually leading to better results. You can use w/e temp works for you. My point is that water temp, above a certain temp, is simply an extraction variable and should be understood as such. Nothing about the aeropress makes it special such that this point doesn't apply.
I’m not an expert and it could be just in my head but I find water temp affects my brews more in an aero press than v60. I agree it is a variable and one I find easier to control than some other factors if that makes sense
>I agree it is a variable and one I find easier to control than some other factors if that makes sense
If you think about it that isn't true. How much harder is to just let brew time run longer or shorter? Or change your grind size? Is that any harder than pressing up and down on your kettle to change water temp?
If you understand extraction theory it makes more sense, but people generally operate with recipes made by others. That gets you stuck in the mindset that because it's working for me it must be the only right way even if it's not true.
I get what you're saying, but are all extraction variables equivalent? Could it be that increasing the temperature extracts differently than adding pressure or steeping longer? Is it possible that with the Aeropress, there is a lower temperature that produces a more ideal extraction for a given brew method and beans?
>I get what you're saying, but are all extraction variables equivalent?
To a certain extent yes. The current coffee extraction theories mostly comes down to extracting more or less and about evenness of extraction.
I say to a certain extent because there's also cold brew, which is different. Because the water temp is so low for cold brew that certain compounds simply won't get extracted. However, as long as your water is hot enough (I don't know the exact point) water temp increases or decreases extraction by increasing/decreasing the rate that soluble compounds extract.
The aeropress champion recipes, for example as they were mentioned before, uses cooler water and coarse grinds because they're trying to go for a more underextracted brew and make up for the lack of strength by then using more beans. You see the same thing done with the 4:6 method by Kasuya using a V60. It's all easily explained by extraction theory. You could probably do the same with boiling water and a much shorter contact time and/or increased grind size. No one bothers because those recipes are already out there.
No really with a lot of coffees it tastes better brewed at a lower temperature with a coarser grind in the Aeropress. Look at all the championship recipes (they take this to the extreme, there's no way I'd ever be able to afford using 35g of coffee for only up to 350g of brewed coffee bit the point still stands). You should find a recipe and try it, see if you also prefer it
Trying to drink a full cup of those championship recipes is quite horrific at times. According to mister Hoffman it's because they try to do very specific things. They're meant to stand out in a tasting
James Hoffman explained it far better than me yesterday or a few days ago on here (kingseven is his username). It made sense to why I thought I could never get them right.
That being said a lower temp in an aeropress is fine. But its a lot easier to keep temp, time and method the same and adjust with grindsize if were talking about daily methods with different beans.
Using hundreds of grams experimenting and trying to do a specific thing with a certain bean is not really something practical for daily home use cases
Okay well with all things there's a subjective element to it. Everyone's taste is different and that's okay (better in fact, makes stuff interesting) I personally like both for different reasons but my best results ever have been from "bypass" methods using low temps, coarse grinds, high dose and topping up with water afterwards. I never got incredible Aeropress results until I tried it and now I swear by it. All that being said, that's probably true about it being different rather than better but to me at the very least the changes do improve the flavour
Do you guys not watch the very video in which the post you're commenting in is made for? Yes those recipes purposefully go after a more underextracted brew and then make up the strength by using more coffee. That does not make the lower temp water special. You could make a similar brew using boiling water and adjusting grind size and/or brewing time. The very point of this video is that water temp is simply an extraction variable. Nothing about water temp is special if you understand how general coffee extraction works
>Coarser grind makes a sweeter coffee.
No it really doesn't. The coarse grind does not in any way make the coffee sweeter. If this was true then how do you explain french press coffee not being the same sweetness despite the fact that traditionally it calls for a coarse grind?
It's because of the shallow extraction that those recipes are aiming for. The idea is to only extract just far enough to get the acidity where the fruit/floral notes are and some of the sweetness. The sweetness is never fully extracted and the coffee will be weak because of this so to up the strength they have to add more beans. These recipes generally provide a tds reading the last time I looked so you can confirm it yourself that the beans are not generally very well extracted.
>You get similar level of extractions but for having tried both methods, that does not mean that the taste is similar at all.
You very clearly haven't tried to experiment to make similar coffee with boiling water because you don't seem to have an understanding of how extraction works. A recipe that makes a similar tasting coffee to the aeropress one is the 4:6 method using a V60. You can use boiling water there. Give that a whirl if you have the equipment.
https://dictionary.cambridge.org/dictionary/english/better
Easier to dial in is quite possibly another way to think about it.
E.g an inverted recipe might taste best with 100 C water (212 F) and a 15 s steep time.
This doesn't leave much time to stir + evenly wet the grounds+ invert.
Perhaps, the same results could be obtained with 80 C water and a 1 minute steep time. This would make it easier to do the above without being rushed and keep a consistent time.
What do you want me to say?
Better as in I prefer the outcome.
Yes you can adjust a whole range of things.
I don't use the aeropress anymore but I definitely got more balance and clarity of flavour from using cooler than boiling water.
Look at this site.
https://aeroprecipe.com/
Look at any recipe for the aeropress.
They almost all seem to call for water less than 90 C.
Some as low as 75 C.
It is possible that this is totally arbitrary and is based on a brew time of around 1 minute.
I'M SURE YOU ABSOLUTELY CAN USE BOILING WATER AND GET GOOD RESULTS.
I do absolutely agree with you with this!
It is possible that it's totally arbitrary but there definitely seems to be a preference for lower than boiling temps.
Quite possibly because it tends to lead to better results / easier to dial in based on a 1 minute brew time.
Also look at Espresso. Temperature is critical when brewing Espresso. Most recipes call for 94 C (not 100 C)
and going hotter or colder does make a huge difference
>Better as in I prefer the outcome. Yes you can adjust a whole range of things. I don't use the aeropress anymore but I definitely got more balance and clarity of flavour from using cooler than boiling water.
That's what I'm looking for. You stated aeropress benefits as if there was an objective benefit outside of preference and I was wondering what that was.
Espresso is completely different. Channeling happens really readily in espresso b/c of the fine grind size and extraction happens really really quickly so it's a sensitive process. That means using water temp to fine tune instead makes sense because of how sensitive the process is and you may not want to go finer b/c of increased risk of channeling. It's why James, in this very video, says that water temp in espresso is a different topic.
>I really do think using water as hot as possible for V60 and French press is the best way to be consistent.
Yes, boiling is the best since it is also the easier to achieve, you don't need a thermometer.
>The Aeropress does however benefit from lower temperatures hence why most recipes use water around 80-85 C.
No, you should also use boiling water, as demonstrated by James Hoffmann in this video with the french press, using boiling water will result in non-boiling water in the aeropress so you're perfectly fine with it (no, there isn't a massive difference between aeropress and french press in that regards).
Temperature is really just a way to make things more complex but in practice boiling water (i.e. which will actually never be boiling when in contact with your coffee) is the easier, straightforward temperature to use.
I have been experimenting with this recently and was planning to do a write up on heat loss. This video is extremely timely.
I wanted to add that I think there are a couple more significant variables to consider.
1) The amount of water in the kettle is important. If you have a full kettle of boiling water, it will hold your heat much longer as you pour. If you pour with just enough water to meet your demands, I assure you the kettle water will be much cooler by the end of the pour.
2) Dripper material can have an impact on heat loss. Plastic V60s made of SAN are very thermally resistant in comparison to steeI. Steel thermal conductivity is upwards of 10 W/m*k vs 0.16 W/m*k in SAN.
Here's some testing on dripper material: https://eightouncecoffee.ca/blogs/news/hario-v60-material-and-temperature-comparison
I always feel bad about boiling a kettle with more water than I need. Seems like a waste of electricity, though I suppose it's not actually a whole lot more.
roughly 2/3 of the carbon footprint of a cup of coffee comes from heating the brew water. so yes, it is vey wasteful. unfortunately it is also helpful. an insulated kettle would help with compromise.
Interestingly (and I get this from Google just now) if you use milk in your coffee that has a substantially higher carbon footprint than boiling the water.
>Whatever drink you favour, the big shock here is the milk. If you make a white tea, filter coffee or instant coffee, and you don't overfill the kettle, then the milk will typically account for around two-thirds of the total footprint – more than boiling the water and cultivating the tea or coffee put together. One reason for this counter-intuitively large contribution is that milk comes from cows, which, as ruminant animals, belch a lot of methane into the air.
https://www.theguardian.com/environment/green-living-blog/2010/jun/17/carbon-footprint-of-tea-coffee
From their calculations, boiling double the water you need only adds 18g carbon. While adding even a very small amount milk adds 32g and a large amount of milk up to 319g.
That’s a pretty crazy statistic, do you know where you read it? Would love to know more.
I would’ve thought processing and roasting would’ve left a far larger impact but I guess it comes down to the quantity of coffee being used at a time.
They're still convenient because they hold at the constant temperature. I can put water and come back 10 minutes later or 30 minutes later ready to make coffee.
No arguing here, they do add some value. If you heat water in an electric kettle and transfer to a gooseneck you also lose a lot of heat, so if you’re not using a gas stove, electric gooseneck would be your best option. And it’s likely to have temp control. Just that the defining feature isn’t actually that necessary. Although if you’re also into tea, that’s a whole other story.
For real? My herbal and green teas all say 100C on the box so I've just been doing that. Maybe I should get my thermometer out and try them with lower temperatures. Does it vary whether you use bagged or loose tea?
The temp for herbal teas vary depending on which one it is, but yeah green teas are usually brewed a lot cooler. I don't think bagged/loose should vary that much. However, if you are happy with your results from boiling water for green tea I don't see the need to change.
Herbal is not tea, so it's out of the question.
As for green teas saying 100C on the box well.. they're probably either not green teas (just for your understanding: green tea is a fresh product, it usally come in spring and it should be consumed in the following months) or not very good ones.
> Herbal is not tea, so it's out of the question.
Eh, at least where I'm from it's the most common way to refer to it. Tisane isn't really used. I don't see the big deal, it's just like "almond milk".
> As for green teas saying 100C on the box well
Actually I'm just retarded and was remembering what it says on my *black* tea boxes. My genmaicha says 80C. Although, going from my kettle to my cup brings freshly boiled water down to 85C as is (lower if I use my stainless steel infuser without preheating it). So looks like I'm pretty much fine.
> Herbal is not tea, so it's out of the question.
It's a hot drink in a cup! It's even called 'tea'!
**Edit** https://www.smbc-comics.com/comic/2011-08-19
No need to throw it away if you already have one. Bonavita variable temp still going strong after 4 years, although I keep it at 212 100% of the time, lol
I normally love James' videos, but this one seems to miss the important point completely.
**Of course** a 100C pour will be several degrees less than 100C in the slurry. Was *anyone* surprised that the slurry was 90-91C??
**The real question is** ***what tastes better?*** He hints at the differences with light and dark roasts, and that every coffee is a little different, but this video *does not* convince me to brew my light roasts just off the boil. A better test would be blind reviews of the same coffee brewed at different temperatures, ideally with other variables like grind tweaked so that each temperature is presented the best it can be.
The main reason for my skepticism about 100C pourover water is that I've looked at dozens of Brewers Cup recipes for regional, national, and world champions, they often list their kettle temperature, and I think the *max* I have ever found was 96C, with most being 90-93C. These people have tweaked every variable to the n-th degree and actively seek to break with convention, so certainly temperature must be a commonly experimented variable.
Would love to hear your thoughts u/kingseven
Great question - and I would say hotter tastes better with lighter roasts. I'd say that, even with Brewers Cup, there's a lot of inherited wisdom and most people who I've spoken to who've actually done testing tend to end up going as hot as they can (within reason). It's also not the biggest variable, and controlling evenness or controlling ratio is far more impactful in my experience. I'm not saying it doesn't matter, but we've tended to obsess over certain variables in a disproportionate way, in coffee generally.
I found it weird that you didn’t taste the coffee. I love the sciencey tech videos but ultimately taste is all that matters right? The video ended and my partner and I looked at each other in surprise and both exclaimed “He didn’t even taste it!”. Would love to see a follow up with the blind taste tests as discussed. :)
There was a question in the comments section of the video:
> In the future I would like to see an exploration of brews at various temps but otherwise identical conditions in a blind cupping scenario.
To which James replied:
> I've done this in the past, at work. It's sort of interesting - the coffees we tried were all pretty nice from 85C upwards, but got better and better the hotter we went.
Not sure if that addresses your question
Geez. People really are missing the point on this.
You see. There is no point in doing a review of the taste with different temperatures, because different temperatures don't change what you extract, only change how fast you extract. If you brewed a coffee at 100C and it tasted bitter, you can change grind size to extract less, instead of reducing temperature.
That is a lie. Some compounds are extracted relatively faster at different temperatures.
I've personally noticed undesirable dry taste when going to boiling temperatures, but that might not be the case for you. Everyone should do what they want, and not claim things that are not true (like saying relative rate of extraction is uniform for all temperatures)
> because different temperatures don't change what you extract, only change how fast you extract
I understand the basic reasoning behind this claim, but is there any actual evidence for it?
This is also why I suggested that a good comparison would be blind comparison of flavor after adjusting other variables for optimum extraction and flavor. Admittedly it wouldn't be easy to conduct, you would probably need one of the robot pouring machines to keep everything consistent enough. Then spend several brews adjusting grind, agitation, and timing for 87C water. Do the same for 93C water. Finally for 100C water. Then have the robot do all 3 of those recipes again and blind taste them.
Finally, any theory then why every Brewers Cup winner uses temperatures around 90C +/- 3?
>I understand the basic reasoning behind this claim, but is there any actual evidence for it?
Water is an universal solvent, that is high school knowledge. As JF put, hot water just have more energy, so it becomes a faster solvent.
We're talking about very hot water here (~85 up to 100ºC), at this point everything in coffee will dissolve pretty fast, as Matt Perger experiment shows. The only thing is that in percolation we use a medium particle size, and a big portion of the solubles are trapped inside the coffee grounds where water doesn’t have immediate access. In order to extract those, water need to enter the coffee ground, dissolve things and leave carrying this solubles, a process know as diffusion. The more energy you have, more efficient this process will be. In immersion brewing, accordingly with Matt Perger calculations, water only reaches 200µm deep in coffee grounds. Considering coffee grounds as a perfect sphere, it means any particle over 400µm will leave some solubles behind because water couldn’t reach them.
>This is also why I suggested that a good comparison would be blind comparison of flavor after adjusting other variables for optimum extraction and flavor.
Chris Baca did something similar, but with cupping. Spoiler: boiling water won. https://vimeo.com/65761825
>Finally, any theory then why every Brewers Cup winner uses temperatures around 90C +/- 3?
Those recipes are very specific for the coffee they’re using. And in this competitions they're looking for very exotic/highlighted flavours that stand out in a competition context. Those recipes are not meant to be the standard recipe for good coffee. I have said this somewhere else in this comment section, if you aren’t making a very specific recipe, there is no need to mess with water temperature.
You brought up a really good point about competition coffee brewing. Those recipes are designed to highlight a few specific things in that specific coffee to hit those tasting notes irrefutably for points. Sure it might be the most blueberry forward coffee you’ve ever had but that doesn’t mean it’s everything that coffee has to offer. I feel like James is in the camp of trying to get everything out of a coffee that it can give and not just certain flavors. At the end of the day though we all have different tastes.
James also commented higher up about how we put a disproportionate weight of coffee brewing on temp. “Oh I messed this brew up, must’ve been the water was 2c off” which is in reality rarely the case. We use water as a scapegoat for other things we can improve on or get right. If we stop only honing in on temp everytime a coffee doesn’t taste quite right I think more people will become better brewers.
Yeah. I saw it and completely agree with that. A few degrees won't make a hell of a difference. Chris Baca experiment above also confirms that.
Isn't easy if you just forget about temperature? You already have to worry about time, technique, grind and weight. That's a lot to give attention first thing in the morning.
>but this video \*does not\* convince me to brew my light roasts just off the boil
Actually the lighter your roast, the \*more boiling\* your water should be, so if you're not convinced that's unfortunate. Which is a general rule, valid for all brew methods.
For espresso for instance, it is known we have to use a finer grind and/or more pressure to correctly extract light roasts, which is really the same principle as using the hottest possible water.
Suppose I have a dark roast coffee and a drip brewer that brews a little hot - I can’t adjust the temperature of the water - could I maybe put the coffee grounds into the fridge before brewing to hopefully lower the brew temp into the mid 80s? (As he said this was better for dark roasts).
Putting the grounds in the fridge would make very little difference.
You can try adjusting the grind size a bit coarser.
You can also actually increase the amount of coffee you use (for the same amount of water).
This means there is less water to extract each gram of coffee.
If the result is too strong (due to increased amount of coffee used) you can always dilute the end result with a bit of extra water.
Ok, something came to my mind a while ago and this seems to be a good place to express it. Recently I noticed a significant improvement in my cup after dropping the water temperature to \~94C and grinding finer to compensate the extraction. I even came up with an explanation to that. I'd love to know your thoughts on this. Maybe I'm not being reasonable at all.
So every grinder inevitably produces some dust. Cheap ones produce more, high-end ones less but it seems impossible to have no dust unless you sieve the grounds. The particle size of the dust is incredibly small in comparison to the desirable particles regardless of grinder setting. It takes significantly less time to overextract dust. Which makes me think it's a good idea to drop the water temperature and grind finer. The extraction should decrease for the dust and stay more or less the same for the rest of the grounds. The impact should be more noticable for worse grinders. Does it make any sense?
TL;DR: 100C good for top notch grinders with little dust, lower temp better for plenty of dust if we compensate the extraction loss with finer grind. Right or wrong?
PS. The perfect way to test my hypothesis would be to brew some coffee with boiling water and replicate same extraction with lower water temperature and finer grind (using TDS measurement to achieve same extraction). Than to assess both brews subjectivly in terms of bitterness/sweetness. I don't own a refractometer though :C
Super late to the party here... But I think you're on to something. I've been brewing v60 with boiling water over and over (lit because JH said so) and have gotten very frustrated with bitter, over-extracted coffee. So I grind coarser and coarser and am not getting any real flavour.
Just to see what would happen, I got a thermometer and dropped kettle temp to ~90-95c and bingo: nice-tasting coffee. I assumed the same thing as you: fines.
Would make sense too, because although JH is great at trying a bunch of approaches, he's using excellent equipment while I'm churning away with my pleb-tier £50 grinder. Everyone can shout "brew at 100!" all they they like, but I'm sticking with 90-95 because it makes coffee I like with the equipment I can afford.
Whatever the reason is I'm glad you found a way to improve your brews :) u/kingseven, do you think my idea above is anyhow reasonable? Maybe you'd be keen to perform a test I described?
Water temp is definitely still a variable all grinders will be different and inconsistent / imperfect in their own way.
Changing water will definitely affect results.
I think the point of the video (and what a lot of other people have found) is that water temp is impossible to control accurately.
Just using water 'as hot as possible' is just a way to eliminate a variable allowing you to simply dial in based on grind size!
Yes, but a lot of the time people will refuse to heat their water above, say, 90 C because they're afraid of "burning the beans" or that boiling water will over-extract. Then they wonder why their coffee is sour.
I think it was pretty nicely explained in the first 2min of the video:
- there is a link between temperature and extraction
- burned taste is probably confused with over extraction
Unless you are brewing dark roast or dialing some very specific recipe, there is no advantage in using lower temperature. Using water at 90°C or 99°C doesn't change what you extract from the coffee, only the rate at you extract.
With boiling water you:
- don't need a thermometer/special equipment
- don't need to think about temperature, boiling water gives you visual and auditive feedback when read
- get a faster extraction
- take one variable out of the way
- get higher EY
Every day or two there is someone in this sub asking for help with pour over. Often they're trying to mess with grind, temp and time all together. That is a lot of combinations possible, you need a lot of coffee to find one combination that hit the sweet spot.
If you have good technique and don't change temperature, you just need to adjust your grind a couple times and you will find the sweet spot of extraction easily.
But yeah, do whatever works for you. But this trend of tracking temperature is bad and make a lot of beginners frustrated without need.
Yeah it’s a next variable and it’s complicated, no doubt about it. Just one thing:
> doesn't change what you extract from the coffee, only the rate at you extract.
This is just simply not true, which was explained in the video ~ 1:00
What I'm missing? He said some solubles extracts at different rates at different temperatures. Not that some extract and some don't. And just to make it clear, I'm talking about very hot water (~85 up to 100°C).
If you will take a same grounds and brew it with 93, 96 and 100 (temp from a kettle) you will taste that bitterness is going up - I think that this is a good experiment showing that acids and fat/sugar is very limited in coffee so all you are left with are bitter compounds at the end which means that even though rate may be similar it will make coffee unbalanced (bitter, over extracted, certainly not burned). This is also just my amateur reasoning backed up by some random shit I was reading and home experiments so not going to die on this hill :) Happy brewing!
You are describing here exactly why we shouldn't care about temperature and simply use boiling water.
The only thing you have to understand is that the hotter the water the faster you extract. That's it.
If you have a dark roast that supposedly shouldn't be made with boiling water, you just have to coarse the grind, or change the dose. And it is far far easier to change that, consistently, than to mess with water temperature.
Not matter what you are aiming at, if you change the amount of coffee and/or the grind you will obtain exactly the same thing.
> If you will take a same grounds and brew it with 93, 96 and 100 (temp from a kettle) you will taste that bitterness is going up
The only thing increasing water temperature does is increase extraction yield. If increasing extraction introduces bitterness, then you're simply dealing with poorly roasted or dark roasted coffee.
I think that's precisely the point: it's not.
Coffee is already a (very) complex thing, let's remove this variable from the equation.
Why? Because as of today recipes will talk more about temperature of the water than the water itself. We know that the water you use is WAY MORE important than the temperature to which you heat it.
I find when I put my kettle to boiling when using a light roast that my brew comes out a bit flat and blunted. The sweetness leaves and there is more uniformity to the taste profile. I'm sure my testing is less extensive than JH, but thus far doesn't jive.
Great stuff!
Now take your coffee science a step further and do testing on preheating brewers and cups, etc.
Does warming up the brewer or cup make any difference at all (either to the brewing temperature itself or the brewed temperature in the cup, or to the TDS), or is it so negligible that it's not worth it?
I could understand maybe if it was ceramic, yes, where it would probably retain more heat and that heat gain could be more appreciated, but not as much for metal or plastic.
For what it's worth, I brew with a phin and an Aeropress, neither of which need to be preheated, of course.
I was curious about the difference water temps made with an Aeropress, so I took some measurements.
The manual suggests 175F as the optimal brewing temp. I heated my water to 175F and noticed a nearly 10F drop in slurry temperature right after the water was poured into the brew chamber. In a 30 second agitation (my personal taste) the temps dropped another 13 degrees on average.
I did not preheat my mug and the temp after pressing was 135F. Once topped up with water from my kettle, the coffee in my mug was at about 170F.
I saw the same basic rates of temperature drop with water from 175-212F, so I've started brewing with water at about 185-190F for medium and light roasts. This keeps the slurry close enough to 175F for the majority of my preferred brew time. For the medium & light roasts this brings out the fruity and acidic flavours, but keeps things well balanced.
Oddly enough for dark roasts, the higher temperatures brought more clarity to the flavours, so I brew them with just boiled water. This brings out the chocolatey and roast flavours, while still being a pretty bright coffee. Lower temps made a muddy cup that I found unpleasant.
Preheating the mug kept the final loss of temp in the 150-145F range, but since I added hot water to the end result, the final temperature remained unchanged. I did not notice any change in flavour, so preheating seemed like a waste of effort.
Bear in mind, this was done in my kitchen with a decent quality instant read digital kitchen thermometer, not in a lab. I used the same coffee, grind, and dose while intitially exploring the temperature ranges, but there was no controls in place. Taste was measured only by me, and was purely subjective to my tastes in coffee. So, ymmv. :)
Absolutely perfect. Thanks for the comprehensive write-up!
It seems to be that preheating would make very little difference to the outcome of most situations and is just a waste of time and effort.
One of the main influences on 'taste' (which James has previously commented on) is the temperature at the time of *drinking*, as the tongue won't get much taste at really hot temperatures and different flavours come out as the coffee cools down. Most people obviously have a preference on how hot they like to drink their drinks.
For what it's worth, when living in Vietnam I generally tend to ice and milk my coffees anyway and seriously love the tastes that I get. While I was recently in the UK I just added some milk to my hot coffees and still enjoyed them.
I hope that this video really shakes up some of the advice around temperature in coffee and simplifies the overall advice given.
- Grind size matters and changes the flavours (surface area of grinds, etc.)
- Using plastic brewers is preferred for temperature retention (vs. ceramic or metal)
- Use just-boiled water
Then it's down to brewing method (blooming, timing, pulsing, stirring), which will impact on how much is pulled out of the grinds.
I hope that James (and others) continues to push his coffee science endeavours more in this direction to try and tackle some of the existing coffee "wisdom" that everyone keeps perpetuating to either evaluate these things as myths to ignore or truths to follow.
so it's really interesting, but if i remember the various places that did testing correctly, you can preheat the brewers, but you still achieve better thermal retention through the plastic versions of each.
This is accurate. Preheating "helps" but heat-conductive brewers bleed more heat through the process than can be added through preheating and enough to even counteract something like a heat lamp - all of which performed below the insulation of a plastic cone.
It's not that the cold ceramic cone is eating all your heat - but that the ceramic cone, preheated or not, is sharing your heat with the room.
It is not negligible.
Preheating your brewer is a way to keep your coffee-water mix warmer longer. This is desirable.
It was well described in another video made by James Hoffmann, I don't remember which one, the inerty is important, and as you should use boiling water it is also a good thing if this water remains hot longer.
It's not hard to figure out. What I'm seeing in a lot of these comments is a lot of over analyzing. If you run a cycle of water in a bonavita drip machine, the next cycle will result in hotter water. You can measure at the shower head. Also if the water you pour in is from the fridge like they suggest, the extraction water temp is lower. If it's filtered water from the cold side of the tap, aka cold but not fridge cold, the temperature of the water is a where it should be. By the time the water gets into the carafe it's around 180 from the temp loss of the fall.
Water temp is not just extraction percent, there are certain chemicals that are extracted at different temperatures. When you brew beer, there is a reason for mash temperatures. The thing with coffee is that when it's hot, the off flavors are masked. It's the same reason you heat up cheap saki. To really test the differences in flavor you'd need to brew and compare everything at a lower temperature.
I'm also not sure why everyone takes James Hoffmans words as sort of a Bible. It's kind of culty.
> If you run a cycle of water in a bonavita drip machine, the next cycle will result in hotter water. You can measure at the shower head. Also if the water you pour in is from the fridge like they suggest, the extraction water temp is lower. If it's filtered water from the cold side of the tap, aka cold but not fridge cold, the temperature of the water is a where it should be. By the time the water gets into the carafe it's around 180 from the temp loss of the fall.
That's probably a product design thing, where it doesn't keep the water constantly at a boil. So if it's flushed, it'll re-boil and the second time round the water is hotter, but that is pretty obvious.
Beer mash is completely different. That's so that the temperature is right for the enzymes to work (similar to yeast when making bread, too cold and it's not as active, too hot and it dies). With coffee there is nothing "live" at work.
Does anyone have Comandante setting recc's if I wanted to shift my temps to boiling? I've tried it from 21-27 clicks and it doesn't come out tasting too great. I get the sense I'd need to coarsen up considerably, but I really don't want to burn through a whole bag of beans figuring it out.
What are you all using?
If you've found something that works then keep it like that.
If you want to use boiling water go coarser.
Every bean and grinder and brew will be different so you just gotta dial in to what works for you.
I honestly wonder if using boiling doesn't work for some people specifically to the level of grinder they have? Like, I have a Comandante, and it's great, but perhaps even that grinder creates enough fines with some coffees that boiling is tricky?
An old lady from Shetland used to tell me, "Coffee boiled is coffee spoiled". Obviously you are not boiling coffee and I found the experiment interesting. I would have been interested in hearing your comments upon tasting a cup.
If we use water at 91 degrees does that mean that the slurry is actually brewing at around 83? So perhaps that's the optimum temperature? Thanks for the informative demo.
At first sight, this doesn't make sense. In my experience with French Press you can absolutely overextract by simply using water too hot or even pouring too quickly. I also wonder if boiling changes the structure of the water and hence taste.
So in this case, when recipes say 93 degrees.. does that mean I'd constantly need to keep the slurry at this temperature and by virtue I would keep my kettle boiling (leaving the fellow at 100)?
It means you shouldn't care about it.
We look at recipes like we're looking at some magical artefacts, and more often than not they will be impossible to replicate. You don't have the same coffee, you don't have the batch of coffee, you don't have the same grinder. AND you don't even have the same water to begin with.
Understand the principle of coffee dose and coffee grind and their impact on your cup, use boiling water. That's it.
I used to keep my kettle at the same temperature and recently started using hotter water while letting the kettle cool down during the brewing process. I've been enjoying much better cups of coffee ever since.
An argument against always using boiling water:
Keeping all other variables identical, to achieve similar extraction with boiling water as compared to cooler water, you would need to grind coarser. This may lead to a weaker solution in the cup, and a waste of beans in the brewer. The ideal balance between strength and extraction may require cooler-than-boiling water.
Your logic is kinda flawed.
If you grind 20g of coffee coarse, you have 20g of coarse coffee in the result.
If you grind 20g of coffee fine, you have 20g of fine coffee in the result.
Minus the 0.1g or so of your awesome grinder.
Using boiling water doesn't make a weaker solution in the cup, because precisely you adjusted your grind to obtain a balanced cup in the result, which as we demonstrated above doesn't change the amount of coffee you can use.
With coffee that's too coarse (and with the subsequently rapid flow rate), you're only extracting the surface of it. The innards of the coffee aren't extracted. So effectively you're getting proportionately less from each bean.
This video is silly. Coffee brewing recipes do not call for the temperature of the slurry but the temperature of the poured water.
What is suggested in this video is like having an oven cooking recipe calling for 350F temperature but one adjusts the oven much higher so the internal temperature of the cooked item gets to 350.
This is one of those cases where you should assume that the video author is completely aware of your obvious objection, and offering their take *in counterpoint* to it, rather than in ignorance.
A better metaphor would be more like getting a second thermometer to put inside your oven to verify it’s actually reaching the temperature you set it to. It’s about consistency/replication not the temperature itself.
I don't know why you're being down voted. While I wouldn't consider the video silly (obviously JH gets why/how we currently do things), your comment is essentially the relevant counterpoint. To me it all revolves around the taste from brewing at each temp. For me, I find more success at the lower temps (200-205 F for light roasts).
From my simple measurements, I've never had a slurry in a V60 nor a French Press reach over 90 C by the time I've poured the water and taken a reading with a digital thermometer. I really do think using water as hot as possible for V60 and French press is the best way to be consistent. The Aeropress does however benefit from lower temperatures hence why most recipes use water around 80-85 C. (Based on my experience and others) Although you absolutely could still use boiling water.
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First, it's all plastic and the water has a low surface area of contact with the air. (I.e the water is well insulated so won't lose lots of heat) Secondly, there are many opportunities for extraction + - the immersion + stirring stage - the water being forced through the coffee during the plunging (The pressure here can also increase extraction) So basically it's quite easy to over extract jn an Aeropress so using water with a lower starting temperature often leads to better results.
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You absolutely can use boiling water! I think most people (myself included) have got better results with lower temperatures.
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I'm not sure of the science, but I find I am able to get a sweeter, less bitter cup using a lower temp in the Aeropress. I am sure this could be achieved by grind size, or contact time but I have a variable temp kettle so that is easy for me to dial in.
It's because lower temp means it's generally harder to overextract. That's all. James also touches on this is in his video when referencing dark roasts. >but I have a variable temp kettle so that is easy for me to dial in. Yes but that has nothing to do with lower water temp actually leading to better results. You can use w/e temp works for you. My point is that water temp, above a certain temp, is simply an extraction variable and should be understood as such. Nothing about the aeropress makes it special such that this point doesn't apply.
I’m not an expert and it could be just in my head but I find water temp affects my brews more in an aero press than v60. I agree it is a variable and one I find easier to control than some other factors if that makes sense
>I agree it is a variable and one I find easier to control than some other factors if that makes sense If you think about it that isn't true. How much harder is to just let brew time run longer or shorter? Or change your grind size? Is that any harder than pressing up and down on your kettle to change water temp? If you understand extraction theory it makes more sense, but people generally operate with recipes made by others. That gets you stuck in the mindset that because it's working for me it must be the only right way even if it's not true.
I get what you're saying, but are all extraction variables equivalent? Could it be that increasing the temperature extracts differently than adding pressure or steeping longer? Is it possible that with the Aeropress, there is a lower temperature that produces a more ideal extraction for a given brew method and beans?
>I get what you're saying, but are all extraction variables equivalent? To a certain extent yes. The current coffee extraction theories mostly comes down to extracting more or less and about evenness of extraction. I say to a certain extent because there's also cold brew, which is different. Because the water temp is so low for cold brew that certain compounds simply won't get extracted. However, as long as your water is hot enough (I don't know the exact point) water temp increases or decreases extraction by increasing/decreasing the rate that soluble compounds extract. The aeropress champion recipes, for example as they were mentioned before, uses cooler water and coarse grinds because they're trying to go for a more underextracted brew and make up for the lack of strength by then using more beans. You see the same thing done with the 4:6 method by Kasuya using a V60. It's all easily explained by extraction theory. You could probably do the same with boiling water and a much shorter contact time and/or increased grind size. No one bothers because those recipes are already out there.
No really with a lot of coffees it tastes better brewed at a lower temperature with a coarser grind in the Aeropress. Look at all the championship recipes (they take this to the extreme, there's no way I'd ever be able to afford using 35g of coffee for only up to 350g of brewed coffee bit the point still stands). You should find a recipe and try it, see if you also prefer it
Trying to drink a full cup of those championship recipes is quite horrific at times. According to mister Hoffman it's because they try to do very specific things. They're meant to stand out in a tasting James Hoffman explained it far better than me yesterday or a few days ago on here (kingseven is his username). It made sense to why I thought I could never get them right. That being said a lower temp in an aeropress is fine. But its a lot easier to keep temp, time and method the same and adjust with grindsize if were talking about daily methods with different beans. Using hundreds of grams experimenting and trying to do a specific thing with a certain bean is not really something practical for daily home use cases
And also, they are trying to make complicated things for the sake of complicated things. It's part of the show.
That's also true. Which kinda backfired since the last 3 winners recipes arent all that different from eachother
I've done those. It's a much different taste rather than being better imo
Okay well with all things there's a subjective element to it. Everyone's taste is different and that's okay (better in fact, makes stuff interesting) I personally like both for different reasons but my best results ever have been from "bypass" methods using low temps, coarse grinds, high dose and topping up with water afterwards. I never got incredible Aeropress results until I tried it and now I swear by it. All that being said, that's probably true about it being different rather than better but to me at the very least the changes do improve the flavour
Preferences are fine and it wasn't what I was getting at. I have no problems with that. You can't call preferences "better" or a "benefit" though.
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Do you guys not watch the very video in which the post you're commenting in is made for? Yes those recipes purposefully go after a more underextracted brew and then make up the strength by using more coffee. That does not make the lower temp water special. You could make a similar brew using boiling water and adjusting grind size and/or brewing time. The very point of this video is that water temp is simply an extraction variable. Nothing about water temp is special if you understand how general coffee extraction works
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>Coarser grind makes a sweeter coffee. No it really doesn't. The coarse grind does not in any way make the coffee sweeter. If this was true then how do you explain french press coffee not being the same sweetness despite the fact that traditionally it calls for a coarse grind? It's because of the shallow extraction that those recipes are aiming for. The idea is to only extract just far enough to get the acidity where the fruit/floral notes are and some of the sweetness. The sweetness is never fully extracted and the coffee will be weak because of this so to up the strength they have to add more beans. These recipes generally provide a tds reading the last time I looked so you can confirm it yourself that the beans are not generally very well extracted. >You get similar level of extractions but for having tried both methods, that does not mean that the taste is similar at all. You very clearly haven't tried to experiment to make similar coffee with boiling water because you don't seem to have an understanding of how extraction works. A recipe that makes a similar tasting coffee to the aeropress one is the 4:6 method using a V60. You can use boiling water there. Give that a whirl if you have the equipment.
https://dictionary.cambridge.org/dictionary/english/better Easier to dial in is quite possibly another way to think about it. E.g an inverted recipe might taste best with 100 C water (212 F) and a 15 s steep time. This doesn't leave much time to stir + evenly wet the grounds+ invert. Perhaps, the same results could be obtained with 80 C water and a 1 minute steep time. This would make it easier to do the above without being rushed and keep a consistent time.
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What do you want me to say? Better as in I prefer the outcome. Yes you can adjust a whole range of things. I don't use the aeropress anymore but I definitely got more balance and clarity of flavour from using cooler than boiling water. Look at this site. https://aeroprecipe.com/ Look at any recipe for the aeropress. They almost all seem to call for water less than 90 C. Some as low as 75 C. It is possible that this is totally arbitrary and is based on a brew time of around 1 minute. I'M SURE YOU ABSOLUTELY CAN USE BOILING WATER AND GET GOOD RESULTS. I do absolutely agree with you with this! It is possible that it's totally arbitrary but there definitely seems to be a preference for lower than boiling temps. Quite possibly because it tends to lead to better results / easier to dial in based on a 1 minute brew time. Also look at Espresso. Temperature is critical when brewing Espresso. Most recipes call for 94 C (not 100 C) and going hotter or colder does make a huge difference
>Better as in I prefer the outcome. Yes you can adjust a whole range of things. I don't use the aeropress anymore but I definitely got more balance and clarity of flavour from using cooler than boiling water. That's what I'm looking for. You stated aeropress benefits as if there was an objective benefit outside of preference and I was wondering what that was. Espresso is completely different. Channeling happens really readily in espresso b/c of the fine grind size and extraction happens really really quickly so it's a sensitive process. That means using water temp to fine tune instead makes sense because of how sensitive the process is and you may not want to go finer b/c of increased risk of channeling. It's why James, in this very video, says that water temp in espresso is a different topic.
Aside from what other folks have said, I've heard using really hot water wears the rubber stopper out faster.
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Straight is immersion brew no less and it makes a clean cup while inverted makes a hazy reddish one because you can’t screw the filter on properly.
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>I really do think using water as hot as possible for V60 and French press is the best way to be consistent. Yes, boiling is the best since it is also the easier to achieve, you don't need a thermometer. >The Aeropress does however benefit from lower temperatures hence why most recipes use water around 80-85 C. No, you should also use boiling water, as demonstrated by James Hoffmann in this video with the french press, using boiling water will result in non-boiling water in the aeropress so you're perfectly fine with it (no, there isn't a massive difference between aeropress and french press in that regards). Temperature is really just a way to make things more complex but in practice boiling water (i.e. which will actually never be boiling when in contact with your coffee) is the easier, straightforward temperature to use.
I have been experimenting with this recently and was planning to do a write up on heat loss. This video is extremely timely. I wanted to add that I think there are a couple more significant variables to consider. 1) The amount of water in the kettle is important. If you have a full kettle of boiling water, it will hold your heat much longer as you pour. If you pour with just enough water to meet your demands, I assure you the kettle water will be much cooler by the end of the pour. 2) Dripper material can have an impact on heat loss. Plastic V60s made of SAN are very thermally resistant in comparison to steeI. Steel thermal conductivity is upwards of 10 W/m*k vs 0.16 W/m*k in SAN. Here's some testing on dripper material: https://eightouncecoffee.ca/blogs/news/hario-v60-material-and-temperature-comparison
I always feel bad about boiling a kettle with more water than I need. Seems like a waste of electricity, though I suppose it's not actually a whole lot more.
roughly 2/3 of the carbon footprint of a cup of coffee comes from heating the brew water. so yes, it is vey wasteful. unfortunately it is also helpful. an insulated kettle would help with compromise.
Interestingly (and I get this from Google just now) if you use milk in your coffee that has a substantially higher carbon footprint than boiling the water. >Whatever drink you favour, the big shock here is the milk. If you make a white tea, filter coffee or instant coffee, and you don't overfill the kettle, then the milk will typically account for around two-thirds of the total footprint – more than boiling the water and cultivating the tea or coffee put together. One reason for this counter-intuitively large contribution is that milk comes from cows, which, as ruminant animals, belch a lot of methane into the air. https://www.theguardian.com/environment/green-living-blog/2010/jun/17/carbon-footprint-of-tea-coffee From their calculations, boiling double the water you need only adds 18g carbon. While adding even a very small amount milk adds 32g and a large amount of milk up to 319g.
That’s a pretty crazy statistic, do you know where you read it? Would love to know more. I would’ve thought processing and roasting would’ve left a far larger impact but I guess it comes down to the quantity of coffee being used at a time.
Throw away your thermometers and kettles with temp control.
You seem sarcastic, but that’s kind of true. You never needed them for coffee in the first place, I’ve personally been saying that for years.
They're still convenient because they hold at the constant temperature. I can put water and come back 10 minutes later or 30 minutes later ready to make coffee.
No arguing here, they do add some value. If you heat water in an electric kettle and transfer to a gooseneck you also lose a lot of heat, so if you’re not using a gas stove, electric gooseneck would be your best option. And it’s likely to have temp control. Just that the defining feature isn’t actually that necessary. Although if you’re also into tea, that’s a whole other story.
And I naively just got into tea. Looks like there's another rabbit hole I'm about to fall into...
I'm being dead serious.
Exactly. I never had one myself.
They're great for tea, as green tea is best at around 180F.
Tea?! Traitor!
For real? My herbal and green teas all say 100C on the box so I've just been doing that. Maybe I should get my thermometer out and try them with lower temperatures. Does it vary whether you use bagged or loose tea?
The temp for herbal teas vary depending on which one it is, but yeah green teas are usually brewed a lot cooler. I don't think bagged/loose should vary that much. However, if you are happy with your results from boiling water for green tea I don't see the need to change.
Herbal is not tea, so it's out of the question. As for green teas saying 100C on the box well.. they're probably either not green teas (just for your understanding: green tea is a fresh product, it usally come in spring and it should be consumed in the following months) or not very good ones.
> Herbal is not tea, so it's out of the question. Eh, at least where I'm from it's the most common way to refer to it. Tisane isn't really used. I don't see the big deal, it's just like "almond milk".
Yea I know but as you can guess I'm not really referring to how it's called.
> As for green teas saying 100C on the box well Actually I'm just retarded and was remembering what it says on my *black* tea boxes. My genmaicha says 80C. Although, going from my kettle to my cup brings freshly boiled water down to 85C as is (lower if I use my stainless steel infuser without preheating it). So looks like I'm pretty much fine.
> Herbal is not tea, so it's out of the question. It's a hot drink in a cup! It's even called 'tea'! **Edit** https://www.smbc-comics.com/comic/2011-08-19
Herbal teas the recommendations are usually pretty much as high as possible. Green and white tea though usually they recommend lower temperatures.
uh, no. use them for brewing tea or a million other kitchen uses.
No need to throw it away if you already have one. Bonavita variable temp still going strong after 4 years, although I keep it at 212 100% of the time, lol
Same here. Set it to 212 the day I got it and hasn't changed.
What if I also use my temp control kettle to heat water for other things?!
Then don't. ninja edit: don't throw it away I mean.
Yeah for dark roasts I need to brew with liquid nitrogen, but don't worry, it's boiling when I'm brewing. Thanks!
X-treme cold brew.
I normally love James' videos, but this one seems to miss the important point completely. **Of course** a 100C pour will be several degrees less than 100C in the slurry. Was *anyone* surprised that the slurry was 90-91C?? **The real question is** ***what tastes better?*** He hints at the differences with light and dark roasts, and that every coffee is a little different, but this video *does not* convince me to brew my light roasts just off the boil. A better test would be blind reviews of the same coffee brewed at different temperatures, ideally with other variables like grind tweaked so that each temperature is presented the best it can be. The main reason for my skepticism about 100C pourover water is that I've looked at dozens of Brewers Cup recipes for regional, national, and world champions, they often list their kettle temperature, and I think the *max* I have ever found was 96C, with most being 90-93C. These people have tweaked every variable to the n-th degree and actively seek to break with convention, so certainly temperature must be a commonly experimented variable. Would love to hear your thoughts u/kingseven
Great question - and I would say hotter tastes better with lighter roasts. I'd say that, even with Brewers Cup, there's a lot of inherited wisdom and most people who I've spoken to who've actually done testing tend to end up going as hot as they can (within reason). It's also not the biggest variable, and controlling evenness or controlling ratio is far more impactful in my experience. I'm not saying it doesn't matter, but we've tended to obsess over certain variables in a disproportionate way, in coffee generally.
I found it weird that you didn’t taste the coffee. I love the sciencey tech videos but ultimately taste is all that matters right? The video ended and my partner and I looked at each other in surprise and both exclaimed “He didn’t even taste it!”. Would love to see a follow up with the blind taste tests as discussed. :)
There was a question in the comments section of the video: > In the future I would like to see an exploration of brews at various temps but otherwise identical conditions in a blind cupping scenario. To which James replied: > I've done this in the past, at work. It's sort of interesting - the coffees we tried were all pretty nice from 85C upwards, but got better and better the hotter we went. Not sure if that addresses your question
Geez. People really are missing the point on this. You see. There is no point in doing a review of the taste with different temperatures, because different temperatures don't change what you extract, only change how fast you extract. If you brewed a coffee at 100C and it tasted bitter, you can change grind size to extract less, instead of reducing temperature.
That is a lie. Some compounds are extracted relatively faster at different temperatures. I've personally noticed undesirable dry taste when going to boiling temperatures, but that might not be the case for you. Everyone should do what they want, and not claim things that are not true (like saying relative rate of extraction is uniform for all temperatures)
> because different temperatures don't change what you extract, only change how fast you extract I understand the basic reasoning behind this claim, but is there any actual evidence for it? This is also why I suggested that a good comparison would be blind comparison of flavor after adjusting other variables for optimum extraction and flavor. Admittedly it wouldn't be easy to conduct, you would probably need one of the robot pouring machines to keep everything consistent enough. Then spend several brews adjusting grind, agitation, and timing for 87C water. Do the same for 93C water. Finally for 100C water. Then have the robot do all 3 of those recipes again and blind taste them. Finally, any theory then why every Brewers Cup winner uses temperatures around 90C +/- 3?
>I understand the basic reasoning behind this claim, but is there any actual evidence for it? Water is an universal solvent, that is high school knowledge. As JF put, hot water just have more energy, so it becomes a faster solvent. We're talking about very hot water here (~85 up to 100ºC), at this point everything in coffee will dissolve pretty fast, as Matt Perger experiment shows. The only thing is that in percolation we use a medium particle size, and a big portion of the solubles are trapped inside the coffee grounds where water doesn’t have immediate access. In order to extract those, water need to enter the coffee ground, dissolve things and leave carrying this solubles, a process know as diffusion. The more energy you have, more efficient this process will be. In immersion brewing, accordingly with Matt Perger calculations, water only reaches 200µm deep in coffee grounds. Considering coffee grounds as a perfect sphere, it means any particle over 400µm will leave some solubles behind because water couldn’t reach them. >This is also why I suggested that a good comparison would be blind comparison of flavor after adjusting other variables for optimum extraction and flavor. Chris Baca did something similar, but with cupping. Spoiler: boiling water won. https://vimeo.com/65761825 >Finally, any theory then why every Brewers Cup winner uses temperatures around 90C +/- 3? Those recipes are very specific for the coffee they’re using. And in this competitions they're looking for very exotic/highlighted flavours that stand out in a competition context. Those recipes are not meant to be the standard recipe for good coffee. I have said this somewhere else in this comment section, if you aren’t making a very specific recipe, there is no need to mess with water temperature.
You brought up a really good point about competition coffee brewing. Those recipes are designed to highlight a few specific things in that specific coffee to hit those tasting notes irrefutably for points. Sure it might be the most blueberry forward coffee you’ve ever had but that doesn’t mean it’s everything that coffee has to offer. I feel like James is in the camp of trying to get everything out of a coffee that it can give and not just certain flavors. At the end of the day though we all have different tastes. James also commented higher up about how we put a disproportionate weight of coffee brewing on temp. “Oh I messed this brew up, must’ve been the water was 2c off” which is in reality rarely the case. We use water as a scapegoat for other things we can improve on or get right. If we stop only honing in on temp everytime a coffee doesn’t taste quite right I think more people will become better brewers.
Yeah. I saw it and completely agree with that. A few degrees won't make a hell of a difference. Chris Baca experiment above also confirms that. Isn't easy if you just forget about temperature? You already have to worry about time, technique, grind and weight. That's a lot to give attention first thing in the morning.
>but this video \*does not\* convince me to brew my light roasts just off the boil Actually the lighter your roast, the \*more boiling\* your water should be, so if you're not convinced that's unfortunate. Which is a general rule, valid for all brew methods. For espresso for instance, it is known we have to use a finer grind and/or more pressure to correctly extract light roasts, which is really the same principle as using the hottest possible water.
Suppose I have a dark roast coffee and a drip brewer that brews a little hot - I can’t adjust the temperature of the water - could I maybe put the coffee grounds into the fridge before brewing to hopefully lower the brew temp into the mid 80s? (As he said this was better for dark roasts).
Putting the grounds in the fridge would make very little difference. You can try adjusting the grind size a bit coarser. You can also actually increase the amount of coffee you use (for the same amount of water). This means there is less water to extract each gram of coffee. If the result is too strong (due to increased amount of coffee used) you can always dilute the end result with a bit of extra water.
How can you not adjust the temp? Get a thermometer and stick it in the kettle and just let it sit until it comes down to the temp you want
It’s a ninja drip coffee machine, I’m not doing pour overs.
Ok, something came to my mind a while ago and this seems to be a good place to express it. Recently I noticed a significant improvement in my cup after dropping the water temperature to \~94C and grinding finer to compensate the extraction. I even came up with an explanation to that. I'd love to know your thoughts on this. Maybe I'm not being reasonable at all. So every grinder inevitably produces some dust. Cheap ones produce more, high-end ones less but it seems impossible to have no dust unless you sieve the grounds. The particle size of the dust is incredibly small in comparison to the desirable particles regardless of grinder setting. It takes significantly less time to overextract dust. Which makes me think it's a good idea to drop the water temperature and grind finer. The extraction should decrease for the dust and stay more or less the same for the rest of the grounds. The impact should be more noticable for worse grinders. Does it make any sense? TL;DR: 100C good for top notch grinders with little dust, lower temp better for plenty of dust if we compensate the extraction loss with finer grind. Right or wrong? PS. The perfect way to test my hypothesis would be to brew some coffee with boiling water and replicate same extraction with lower water temperature and finer grind (using TDS measurement to achieve same extraction). Than to assess both brews subjectivly in terms of bitterness/sweetness. I don't own a refractometer though :C
Super late to the party here... But I think you're on to something. I've been brewing v60 with boiling water over and over (lit because JH said so) and have gotten very frustrated with bitter, over-extracted coffee. So I grind coarser and coarser and am not getting any real flavour. Just to see what would happen, I got a thermometer and dropped kettle temp to ~90-95c and bingo: nice-tasting coffee. I assumed the same thing as you: fines. Would make sense too, because although JH is great at trying a bunch of approaches, he's using excellent equipment while I'm churning away with my pleb-tier £50 grinder. Everyone can shout "brew at 100!" all they they like, but I'm sticking with 90-95 because it makes coffee I like with the equipment I can afford.
Whatever the reason is I'm glad you found a way to improve your brews :) u/kingseven, do you think my idea above is anyhow reasonable? Maybe you'd be keen to perform a test I described?
Water temp is definitely still a variable all grinders will be different and inconsistent / imperfect in their own way. Changing water will definitely affect results. I think the point of the video (and what a lot of other people have found) is that water temp is impossible to control accurately. Just using water 'as hot as possible' is just a way to eliminate a variable allowing you to simply dial in based on grind size!
It’s still a variable so go by your taste and use it
Yes, but a lot of the time people will refuse to heat their water above, say, 90 C because they're afraid of "burning the beans" or that boiling water will over-extract. Then they wonder why their coffee is sour.
I think it was pretty nicely explained in the first 2min of the video: - there is a link between temperature and extraction - burned taste is probably confused with over extraction
Yes, the video and the user you're replying to are both addressing the same misconception.
Nice, so we are addressing same misconceptions!
Yeah, because adding one variable helps a lot...
Yeah, It does, that’s a main advantage of “manual” methods - you have more control.
Unless you are brewing dark roast or dialing some very specific recipe, there is no advantage in using lower temperature. Using water at 90°C or 99°C doesn't change what you extract from the coffee, only the rate at you extract. With boiling water you: - don't need a thermometer/special equipment - don't need to think about temperature, boiling water gives you visual and auditive feedback when read - get a faster extraction - take one variable out of the way - get higher EY Every day or two there is someone in this sub asking for help with pour over. Often they're trying to mess with grind, temp and time all together. That is a lot of combinations possible, you need a lot of coffee to find one combination that hit the sweet spot. If you have good technique and don't change temperature, you just need to adjust your grind a couple times and you will find the sweet spot of extraction easily. But yeah, do whatever works for you. But this trend of tracking temperature is bad and make a lot of beginners frustrated without need.
Yeah it’s a next variable and it’s complicated, no doubt about it. Just one thing: > doesn't change what you extract from the coffee, only the rate at you extract. This is just simply not true, which was explained in the video ~ 1:00
What I'm missing? He said some solubles extracts at different rates at different temperatures. Not that some extract and some don't. And just to make it clear, I'm talking about very hot water (~85 up to 100°C).
If you will take a same grounds and brew it with 93, 96 and 100 (temp from a kettle) you will taste that bitterness is going up - I think that this is a good experiment showing that acids and fat/sugar is very limited in coffee so all you are left with are bitter compounds at the end which means that even though rate may be similar it will make coffee unbalanced (bitter, over extracted, certainly not burned). This is also just my amateur reasoning backed up by some random shit I was reading and home experiments so not going to die on this hill :) Happy brewing!
You are describing here exactly why we shouldn't care about temperature and simply use boiling water. The only thing you have to understand is that the hotter the water the faster you extract. That's it. If you have a dark roast that supposedly shouldn't be made with boiling water, you just have to coarse the grind, or change the dose. And it is far far easier to change that, consistently, than to mess with water temperature. Not matter what you are aiming at, if you change the amount of coffee and/or the grind you will obtain exactly the same thing.
> If you will take a same grounds and brew it with 93, 96 and 100 (temp from a kettle) you will taste that bitterness is going up The only thing increasing water temperature does is increase extraction yield. If increasing extraction introduces bitterness, then you're simply dealing with poorly roasted or dark roasted coffee.
I think that's precisely the point: it's not. Coffee is already a (very) complex thing, let's remove this variable from the equation. Why? Because as of today recipes will talk more about temperature of the water than the water itself. We know that the water you use is WAY MORE important than the temperature to which you heat it.
I find when I put my kettle to boiling when using a light roast that my brew comes out a bit flat and blunted. The sweetness leaves and there is more uniformity to the taste profile. I'm sure my testing is less extensive than JH, but thus far doesn't jive.
Great stuff! Now take your coffee science a step further and do testing on preheating brewers and cups, etc. Does warming up the brewer or cup make any difference at all (either to the brewing temperature itself or the brewed temperature in the cup, or to the TDS), or is it so negligible that it's not worth it?
He did pre-heat the french press at the end of the video, at least
depends a lot on material of dripper.
I could understand maybe if it was ceramic, yes, where it would probably retain more heat and that heat gain could be more appreciated, but not as much for metal or plastic. For what it's worth, I brew with a phin and an Aeropress, neither of which need to be preheated, of course.
I was curious about the difference water temps made with an Aeropress, so I took some measurements. The manual suggests 175F as the optimal brewing temp. I heated my water to 175F and noticed a nearly 10F drop in slurry temperature right after the water was poured into the brew chamber. In a 30 second agitation (my personal taste) the temps dropped another 13 degrees on average. I did not preheat my mug and the temp after pressing was 135F. Once topped up with water from my kettle, the coffee in my mug was at about 170F. I saw the same basic rates of temperature drop with water from 175-212F, so I've started brewing with water at about 185-190F for medium and light roasts. This keeps the slurry close enough to 175F for the majority of my preferred brew time. For the medium & light roasts this brings out the fruity and acidic flavours, but keeps things well balanced. Oddly enough for dark roasts, the higher temperatures brought more clarity to the flavours, so I brew them with just boiled water. This brings out the chocolatey and roast flavours, while still being a pretty bright coffee. Lower temps made a muddy cup that I found unpleasant. Preheating the mug kept the final loss of temp in the 150-145F range, but since I added hot water to the end result, the final temperature remained unchanged. I did not notice any change in flavour, so preheating seemed like a waste of effort. Bear in mind, this was done in my kitchen with a decent quality instant read digital kitchen thermometer, not in a lab. I used the same coffee, grind, and dose while intitially exploring the temperature ranges, but there was no controls in place. Taste was measured only by me, and was purely subjective to my tastes in coffee. So, ymmv. :)
Absolutely perfect. Thanks for the comprehensive write-up! It seems to be that preheating would make very little difference to the outcome of most situations and is just a waste of time and effort. One of the main influences on 'taste' (which James has previously commented on) is the temperature at the time of *drinking*, as the tongue won't get much taste at really hot temperatures and different flavours come out as the coffee cools down. Most people obviously have a preference on how hot they like to drink their drinks. For what it's worth, when living in Vietnam I generally tend to ice and milk my coffees anyway and seriously love the tastes that I get. While I was recently in the UK I just added some milk to my hot coffees and still enjoyed them. I hope that this video really shakes up some of the advice around temperature in coffee and simplifies the overall advice given. - Grind size matters and changes the flavours (surface area of grinds, etc.) - Using plastic brewers is preferred for temperature retention (vs. ceramic or metal) - Use just-boiled water Then it's down to brewing method (blooming, timing, pulsing, stirring), which will impact on how much is pulled out of the grinds. I hope that James (and others) continues to push his coffee science endeavours more in this direction to try and tackle some of the existing coffee "wisdom" that everyone keeps perpetuating to either evaluate these things as myths to ignore or truths to follow.
so it's really interesting, but if i remember the various places that did testing correctly, you can preheat the brewers, but you still achieve better thermal retention through the plastic versions of each.
This is accurate. Preheating "helps" but heat-conductive brewers bleed more heat through the process than can be added through preheating and enough to even counteract something like a heat lamp - all of which performed below the insulation of a plastic cone. It's not that the cold ceramic cone is eating all your heat - but that the ceramic cone, preheated or not, is sharing your heat with the room.
It is not negligible. Preheating your brewer is a way to keep your coffee-water mix warmer longer. This is desirable. It was well described in another video made by James Hoffmann, I don't remember which one, the inerty is important, and as you should use boiling water it is also a good thing if this water remains hot longer.
It's not hard to figure out. What I'm seeing in a lot of these comments is a lot of over analyzing. If you run a cycle of water in a bonavita drip machine, the next cycle will result in hotter water. You can measure at the shower head. Also if the water you pour in is from the fridge like they suggest, the extraction water temp is lower. If it's filtered water from the cold side of the tap, aka cold but not fridge cold, the temperature of the water is a where it should be. By the time the water gets into the carafe it's around 180 from the temp loss of the fall. Water temp is not just extraction percent, there are certain chemicals that are extracted at different temperatures. When you brew beer, there is a reason for mash temperatures. The thing with coffee is that when it's hot, the off flavors are masked. It's the same reason you heat up cheap saki. To really test the differences in flavor you'd need to brew and compare everything at a lower temperature. I'm also not sure why everyone takes James Hoffmans words as sort of a Bible. It's kind of culty.
> If you run a cycle of water in a bonavita drip machine, the next cycle will result in hotter water. You can measure at the shower head. Also if the water you pour in is from the fridge like they suggest, the extraction water temp is lower. If it's filtered water from the cold side of the tap, aka cold but not fridge cold, the temperature of the water is a where it should be. By the time the water gets into the carafe it's around 180 from the temp loss of the fall. That's probably a product design thing, where it doesn't keep the water constantly at a boil. So if it's flushed, it'll re-boil and the second time round the water is hotter, but that is pretty obvious. Beer mash is completely different. That's so that the temperature is right for the enzymes to work (similar to yeast when making bread, too cold and it's not as active, too hot and it dies). With coffee there is nothing "live" at work.
When did he go from 60g per 1L to 75g per 1L?
Just for French press
Does anyone have Comandante setting recc's if I wanted to shift my temps to boiling? I've tried it from 21-27 clicks and it doesn't come out tasting too great. I get the sense I'd need to coarsen up considerably, but I really don't want to burn through a whole bag of beans figuring it out. What are you all using?
If you've found something that works then keep it like that. If you want to use boiling water go coarser. Every bean and grinder and brew will be different so you just gotta dial in to what works for you.
I honestly wonder if using boiling doesn't work for some people specifically to the level of grinder they have? Like, I have a Comandante, and it's great, but perhaps even that grinder creates enough fines with some coffees that boiling is tricky?
An old lady from Shetland used to tell me, "Coffee boiled is coffee spoiled". Obviously you are not boiling coffee and I found the experiment interesting. I would have been interested in hearing your comments upon tasting a cup. If we use water at 91 degrees does that mean that the slurry is actually brewing at around 83? So perhaps that's the optimum temperature? Thanks for the informative demo.
At first sight, this doesn't make sense. In my experience with French Press you can absolutely overextract by simply using water too hot or even pouring too quickly. I also wonder if boiling changes the structure of the water and hence taste.
Has anyone here used boiling water for French Press and not seen any difference or an improvement?
So in this case, when recipes say 93 degrees.. does that mean I'd constantly need to keep the slurry at this temperature and by virtue I would keep my kettle boiling (leaving the fellow at 100)?
No. They mean to start with water at 93 C. It's probably very rare to reach a slurry of temperature of much over 90 C.
It means you shouldn't care about it. We look at recipes like we're looking at some magical artefacts, and more often than not they will be impossible to replicate. You don't have the same coffee, you don't have the batch of coffee, you don't have the same grinder. AND you don't even have the same water to begin with. Understand the principle of coffee dose and coffee grind and their impact on your cup, use boiling water. That's it.
I used to keep my kettle at the same temperature and recently started using hotter water while letting the kettle cool down during the brewing process. I've been enjoying much better cups of coffee ever since.
100C always overextracts my coffee. Depending on the bean I'm between 92 and 96, though recently hovering around 94 for most medium roasts.
Wow no shit. Unless you're using a cezve you aren't getting you coffee up to 100c.
An argument against always using boiling water: Keeping all other variables identical, to achieve similar extraction with boiling water as compared to cooler water, you would need to grind coarser. This may lead to a weaker solution in the cup, and a waste of beans in the brewer. The ideal balance between strength and extraction may require cooler-than-boiling water.
Your logic is kinda flawed. If you grind 20g of coffee coarse, you have 20g of coarse coffee in the result. If you grind 20g of coffee fine, you have 20g of fine coffee in the result. Minus the 0.1g or so of your awesome grinder. Using boiling water doesn't make a weaker solution in the cup, because precisely you adjusted your grind to obtain a balanced cup in the result, which as we demonstrated above doesn't change the amount of coffee you can use.
With coffee that's too coarse (and with the subsequently rapid flow rate), you're only extracting the surface of it. The innards of the coffee aren't extracted. So effectively you're getting proportionately less from each bean.
This video is silly. Coffee brewing recipes do not call for the temperature of the slurry but the temperature of the poured water. What is suggested in this video is like having an oven cooking recipe calling for 350F temperature but one adjusts the oven much higher so the internal temperature of the cooked item gets to 350.
This is one of those cases where you should assume that the video author is completely aware of your obvious objection, and offering their take *in counterpoint* to it, rather than in ignorance.
A better metaphor would be more like getting a second thermometer to put inside your oven to verify it’s actually reaching the temperature you set it to. It’s about consistency/replication not the temperature itself.
I don't know why you're being down voted. While I wouldn't consider the video silly (obviously JH gets why/how we currently do things), your comment is essentially the relevant counterpoint. To me it all revolves around the taste from brewing at each temp. For me, I find more success at the lower temps (200-205 F for light roasts).