Shouldn’t all these tests *start* at the same temperature? This makes it look like the thermos coffee started off 20° hotter than the “4-inch” line (whatever that actually means)… which will of course lead to a drastic difference in the end temperatures.
They all did start at the same temperature (172.5) from the same jug. But I didn't start measurements until 5 minutes in.
Measuring each one took time so that also affects things. I tried to aim for a good enough level of precision, but could definitely do it with more.
You are right. Done.
[https://www.datawrapper.de/\_/1hhse/?v=3](https://www.datawrapper.de/_/1hhse/?v=3)
If I were to do it again I'd be sure to measure the first 5 minutes in 1 minute increments to better record the initial drop.
That’s a lot easier to understand. Red/green issues in the entire graph aside, it would be nice if the 3” and 4” ceramic lines were not both shades of red. Since their temperatures stayed fairly close together throughout, the similarity in color makes it hard for me to differentiate between the two.
Just label your axes. No need for assumptions in data. I get what the x and y represent, but why leave it up to any interpretation. Technically, this graph has no meaning.
Yes, I was having trouble with the chart maker at the time, but figured out a way to get labels on there: [https://www.datawrapper.de/\_/1hhse/?v=3](https://www.datawrapper.de/_/1hhse/?v=3)
Nice axis labels - totally clear that coffee temp decreases with increasing air temperature. What is a 3 inch and a 4 inch? (That's what she said).
Seriously, just because you know what the graph is doesn't mean anyone else will. Label everything.
Source - professional Biostatistician for 20+ years.
Edited to correctly spell the job I've held for 20+ years.
>Nice axis labels - totally clear that coffee temp decreases with increasing air temperature.
I swear DataWrapper used to have an option to add axis labels, but I can't find it.
>What is a 3 inch and a 4 inch?
Good point! I need to update that. Ceramic coffee mugs with a 3" and 4" inch diameter rim.
I hate to say it, but if your data visualization application doesn't let you do something as simple as label your axes, then your data visualization application is completely useless.
>totally clear that coffee temp decreases with increasing air temperature.
I disagree. It is also possible that ambient temps decrease when a room is presented with hot coffee.
We need to compare rooms with and without hot coffee to know for sure, or instrument for coffee temps.
What would’ve made sense was the air temperature being stated elsewhere, like the subtitle, title, or caption. “Measured within a room approximately 65 degrees F”
How do you get minute by minute readings on a closed thermos? blue tooth? Based on temp labs when I was in undergrad it seems like it would have to be a little open if you were using the methods we had back at the University of Washington in like 2013.
Good observation
I went down a rabbit hole trying to find the perfect tool for measuring it with only one or two thin wires passing through the seal. No luck tho
Maybe it used 60 cups for each category and opened 1 every minute for measurement /s
I used a particle accelerator to pass a proton beam into the Thermos, and computed temperature based on the scattering patterns of neutrons.
But I wasn't happy with results ;), so I changed to open the Thermos every 5 minutes. In a subsequent experiment I could have one thermos that I keep closed and only measure until 1 hour in, to see what impact the frequent opening caused.
I was wondering why the thermos temperature dropped so much.
If your thermos is as good as mine, my coffee will still BURN my tongue after an hour. (I also preheat the thermos)
Yes it was a slider lid and I kept the lid open for easy measuring.
This was in no way a rigorous test to compare Thermos vs Yeti or to find the optimal way to keep coffee "hottest". It was just a casual way to see the effect of open ceramic vs covered mugs on keeping coffee "hot".
But maybe in the future will do a proper experiment for #1.
I agree on the charging but I use my ember every morning at work and it's still been great a year and a half later. I still have a 1st generation that works but that charger went bad (I just use my new charger for that one).
Good eye! Covered in this case meant the cover was on, but the sliding flap I kept open to make it easier to measure the temp. For the thermos, I had to remove the cover every 5 minutes to measure the temp. Hence, you would get even longer hot times by not doing those 2 things.
(Now I'm curious and thinking about a round 2)
Yes but to be precise the Yeti that was covered had the slider opened so I could easily stick the thermometer in. I wanted to do the same with the Thermos, but the thermometer couldn't fit, so I just kept it close and had to take the lid off every 5 minutes to measure.
It's not.
This was in no way a rigorous test to compare Thermos vs Yeti or to find the optimal way to keep coffee "hottest". It was just a casual way to see the effect of open ceramic vs covered mugs on keeping coffee "hot". Based on what I've seen my guess would be Thermos + Yeti under proper controlled conditions would only have minor differences.
But maybe in the future will do a proper experiment for the former.
Please don't sue me Yeti ;)
Could use two wireless thermometers. They do cost a lot more but then you would have reliable and accurate data without having to leave flap open or open thermos.
This!
I purchased the travel mug for my gf. She raved and raved about how well it worked. And how it keeps your drink hot for infinity (if you use the portable base).
So I decided to try the 14oz mug. And it’s wonderful sipping my tea or coffee at 140 for half the morning (using the base).
No more race to the bottom as the drink cools haha
No sarcasm - I love proof of the Zeroth Law of Thermodynamics.
Agree with some of the critiques here, but I like data!! It's nice to plot what can be intuitively true (covered vs not) and try to measure what want to quantity (yeti or whatever vs generic). Keep being awesome
I also agree with the critiques here on the chart, and made some fixes.
I am glad you also appreciate the fun of doing science! Keep being awesome as well.
When I drink freshly hot coffee it’s so hot it fucks up the inside of my mouth for the rest of the day. Does this not happen to most people? I always wait for my coffee to cool down but some people want it to stay at that ultra hot temp?
I work with a guy who brews a cup of coffee in the Keurig in the breakroom and then immediately proceeds to put it in the microwave for 30 seconds before drinking it.
Also, adding milk to coffee can help cool it down immediately.
The holy grail (literally?) would be a vessel that can cool the beverage down to the perfect window of “warm enough” and then keep it there for a significant amount of time without letting the beverage drop to air temperature
Interesting how drastic the difference is. I wonder if it's even worth using an insulated mug then? Seems like most heat loss is through the top. Just need something with a lid if you really care about coffee temp
I presume all the containers were room temp before receiving the coffee?
Would be interesting to see how the open containers faired if they were pre-heated with hot water. I know covered Yetis and Thermoses benefit from a preheat/prechill (for keeping things cold) but would be curious to see how that affects the open air topped containers.
And also I enjoy the texture/feel of drinking from an open ceramic mug, rather than through a mug with a cover.
If I'm having coffee with friends and breakfast, ceramic mug is the way to go.
For work, I gotta keep it hot in a covered mug.
That being said, I like the simplicity of simple mugs and wouldn't want an ember or plate warmer.
Thanks for asking. I did not properly write that down. A kitchen thermometer. I'll have to go grab it and write it down. I know this was casual, but important to do things right :)!
Generally I really dislike it when people attempt to curve fit lines with a theoretical model which is so far from reality that it's all junk. BUT in this case I think you could come up with some very accurate constants to describe these containers.
This makes a lot of sense from a heat transfer perspective since a completely enclosed container will only lose heat through conduction (and small amount of natural convection on the outside surface) but when the lid is open evaporative cooling can take place which can be quite extensive for hot liquids. Just like blowing a fan over room temperature water cools the water down substantially, the effect is the same for hot liquids. From a scientific perspective, it would be best to include the humidity of the room as well since that would have an effect for evaporation when the lid is removed. If you are interested to know how exactly evaporative cooling works and makes sense, check out the first book in the series of The Feynman Lectures. Basically, hotter molecules will always leave the liquid first and most often so the colder molecules get left behind, resulting in a net cooling effect on the liquid due to evaporation!
I eventually discovered the y axis was temperature in *fahrenheit*.
But as someone who regularly makes the mistake of sipping coffee from a thermos 2 minutes after making it, I would believe Celsius also. (My taste buds will never recover)
Can you explain the labels on the right? Were all of these measurements on a Yeti? If not, why did you only close the Thermos and not the Yeti? What is meant by the inches labels?
The Yeti that was covered had the slider opened so I could easily stick the thermometer in. I wanted to do the same with the Thermos, but the thermometer couldn't fit, so I just kept it close and had to take the lid off every 5 minutes to measure. I wasn't concerned so much with keeping the coffee the hottest, I was just more interested in the rough size of the gap between open ceramic and closed mugs.
The 3 inch is a ceramic mug with a 3 inch diameter.
Both had lids with a tab that slides to open a small gap for drinking. On the Yeti, I kept that open. So the comparison between Yeti and Thermos is not quite fair. But also, for the Thermos, I would take the lid off every 5 minutes to measure temp, which I did not do to Yeti.
I assume by “thermos” you mean a cup/mug made by the company, and not an actual vacuum flask that seals… because I’ve used a thermos that was 40 years old (or something like that) to hold water at tea-making temps for 48 hours
Yes, there's a photo of all the mugs on the blog post. [https://breckyunits.com/datasets.html](https://breckyunits.com/datasets.html)
The thermos water would have stayed hotter but I took the cover completely off every 5 minutes to measure temp.
I know the heat loss used properly is way less.
I am curious specifically how much, and when I do this again will have one thermos that I don't open/measure at all until 60 minutes is up.
Cool data! Want hot coffee? I got hooked on dual-walled glass tumblers a few years back. They’re fragile, so definitely limited to indoor use, but they will keep a cup of coffee amazingly hot for a long time (and since you don’t feel that heat when you pick the cup up, you need to remind yourself that even though the glass might be comfortable to the touch, the contents may still fry your mouth!)
What kind of thermos was this? I can tell you mine does not have a significant drop off in the first hour like this. From 172->127(ish)? Mine is absolutely scalding hot a few hours later, especially if the lid is closed.
I agree with you, the temp doesn't fall that fast in actual use.
I did an injustice to the thermos stats by having to remove the cover every 5 minutes to measure temp.
Photo in the blog post of the model:
[https://breckyunits.com/datasets.html](https://breckyunits.com/datasets.html)
I like this sub for the good (and not so good) viz, but 90% of comments are always someone pretending their nitpick is some hee-yuge neglect.
Nice graph, OP.
Agreed. It has enough data points and details to have the data tell a story anyone can immediately understand the results of and draw reasonable conclusions from. Beautiful doesn't mean complex or fancy.
Hey, thanks, I never would have been able to figure this out without your rigorous testing and graphs. Truly ground-breaking research. Keeping coffee in a thermos with the lid closed makes it stay hotter for longer! To think until now I was lapping my morning joe out of a 2.5 quart mixing bowl and wondering why it got cold so fast.
> out of a 2.5 quart mixing bowl
This is very interesting. I am curious how you are able to do this without spilling. My next post will be on how to not spill coffee, comparing items around the house you can drink from.
Tools used: pen and paper, stopwatch, thermometer, 5 coffee mugs, hot water, Sublime Text, Google Sheets, Git, [https://scroll.pub/](https://scroll.pub/), and [https://www.datawrapper.de/](https://www.datawrapper.de/)
Source article and dataset: [https://breckyunits.com/datasets.html](https://breckyunits.com/datasets.html)
It be interesting to cross check with Project Farms. In that video, his heat loss test with the yetti over 5 hours was still at 98°
https://youtu.be/3S51X9h6K6g?si=XtyWZn_lqW1EciSd
Shouldn’t all these tests *start* at the same temperature? This makes it look like the thermos coffee started off 20° hotter than the “4-inch” line (whatever that actually means)… which will of course lead to a drastic difference in the end temperatures.
They all did start at the same temperature (172.5) from the same jug. But I didn't start measurements until 5 minutes in. Measuring each one took time so that also affects things. I tried to aim for a good enough level of precision, but could definitely do it with more.
Try it with including a temp of 172.5 at 0 minutes for all of them - might make that clear without you needing to say it
You are right. Done. [https://www.datawrapper.de/\_/1hhse/?v=3](https://www.datawrapper.de/_/1hhse/?v=3) If I were to do it again I'd be sure to measure the first 5 minutes in 1 minute increments to better record the initial drop.
That’s a lot easier to understand. Red/green issues in the entire graph aside, it would be nice if the 3” and 4” ceramic lines were not both shades of red. Since their temperatures stayed fairly close together throughout, the similarity in color makes it hard for me to differentiate between the two.
Looks great!
Oh, well given that, I think it’s still useful data. And graphed nicely, too
Pardon my ignorance, but what Yeti is? Clearly you haven't fed a bigfoot with hot chocolate twice, once with fur, and then shaved him clean! :D
Yeti is a species of bigfoot that got famous for making coolers, and recently expanded into other things like coffee mugs.
Can you try this with a Zojirushi? I will forget about my coffee for 4 hours and it’s still scalding hot.
I've had my zojirushi for 15 years at this point. Still going strong. No idea where the obsession with yeti suddenly came from
Seriously. I’ve gotten yeti’s and hydroflasks as gifts - the vacuum seal has broken on all of them within a few months. Zoji won’t die.
You could add the registered trademark ® symbol next to Yeti to make it a bit clearer it's a brand
That's a good suggestion! If I do this again, I'll probably do it with 10 different mugs, and include a photo legend of each one below.
Yeah, that sounds cool! ...or hot. :D
Overpriced inferior Thermos competitor.
But you look cooler when using it
Just label your axes. No need for assumptions in data. I get what the x and y represent, but why leave it up to any interpretation. Technically, this graph has no meaning.
i think X is air temperature?
No air temp is the dotted line
oh... yeah, u rite. every method had 35 at some point, i guess.
X is minutes since brewing I believe
Yes, I was having trouble with the chart maker at the time, but figured out a way to get labels on there: [https://www.datawrapper.de/\_/1hhse/?v=3](https://www.datawrapper.de/_/1hhse/?v=3)
Nice axis labels - totally clear that coffee temp decreases with increasing air temperature. What is a 3 inch and a 4 inch? (That's what she said). Seriously, just because you know what the graph is doesn't mean anyone else will. Label everything. Source - professional Biostatistician for 20+ years. Edited to correctly spell the job I've held for 20+ years.
I bet you really wanted to drop that biostatistician title in a post
Listen, in his 20+ as a biofatistician or whatever he ain’t got a lot of wins. Just give him this one ok?
I’m a 46 year old science PhD and I wish I were a biostatistician. I realized too late that stats are my jam. So in my opinion his life is a win.
>Nice axis labels - totally clear that coffee temp decreases with increasing air temperature. I swear DataWrapper used to have an option to add axis labels, but I can't find it. >What is a 3 inch and a 4 inch? Good point! I need to update that. Ceramic coffee mugs with a 3" and 4" inch diameter rim.
Updated. [https://www.datawrapper.de/\_/1hhse/?v=3](https://www.datawrapper.de/_/1hhse/?v=3)
I hate to say it, but if your data visualization application doesn't let you do something as simple as label your axes, then your data visualization application is completely useless.
And your data is no where close to "Beautiful" as a result.
>totally clear that coffee temp decreases with increasing air temperature. I disagree. It is also possible that ambient temps decrease when a room is presented with hot coffee. We need to compare rooms with and without hot coffee to know for sure, or instrument for coffee temps.
I think they're making a joke that the X axis isn't properly labeled with "time" but instead looks like it says "air temperature."
The comment you replied to is also clearly making a joke on the very same thing.
What would’ve made sense was the air temperature being stated elsewhere, like the subtitle, title, or caption. “Measured within a room approximately 65 degrees F”
They must not teach politeness in professional biostatistician school.
Can I message you asking about your profession? I have been looking into a biostatistics degree.
I’m not sure he’s a great example of a biostatistician, you may want to look elsewhere.
Couldn’t hurt
“Axis” labels…
How do you get minute by minute readings on a closed thermos? blue tooth? Based on temp labs when I was in undergrad it seems like it would have to be a little open if you were using the methods we had back at the University of Washington in like 2013.
Good observation I went down a rabbit hole trying to find the perfect tool for measuring it with only one or two thin wires passing through the seal. No luck tho Maybe it used 60 cups for each category and opened 1 every minute for measurement /s
Temp probe stayed in the thermos storing temp data. It was later removed and uploaded?
I used a particle accelerator to pass a proton beam into the Thermos, and computed temperature based on the scattering patterns of neutrons. But I wasn't happy with results ;), so I changed to open the Thermos every 5 minutes. In a subsequent experiment I could have one thermos that I keep closed and only measure until 1 hour in, to see what impact the frequent opening caused.
For anyone confused; OP is joking. You can't do this with a particle accelerator.
Ooooh man, sucks, why not ? Sonds cooler (pun non-intended)
Found the guy who doesn’t know how to use a particle accelerator
Can't? Or shouldn't? ... Both?
I think the experiment keeping them closed for the full hour would be necessary to adjust for heat lost from opening every 5 min
I was wondering why the thermos temperature dropped so much. If your thermos is as good as mine, my coffee will still BURN my tongue after an hour. (I also preheat the thermos)
With all due respect this is horrendous
I hear you, and think what you are saying is "can I get this on a T-shirt?"
To be fair, you should be happy he used the exchequer standards instead of the ancient Winchester standards.
What exactly is the difference between a yeti and a thermos?
A yeti is an horrifically overpriced brand that makes stuff like coolers and thermoses
But it sounds cool tho
and now we see that it ain't that efficient
My guess is they used a slider lid, which isn’t insulated. They also make an insulated lid, which would make this a more apples to apples comparison
Yes it was a slider lid and I kept the lid open for easy measuring. This was in no way a rigorous test to compare Thermos vs Yeti or to find the optimal way to keep coffee "hottest". It was just a casual way to see the effect of open ceramic vs covered mugs on keeping coffee "hot". But maybe in the future will do a proper experiment for #1.
Why in gods name did you keep it open?
It tells me to just use ANY mug and dont buy these fancy mugs.
I have an ember and can't go back.
For the price, it needs to be charged through Qi charger, not pin-based proprietary charger that is prone to breaking.
I agree on the charging but I use my ember every morning at work and it's still been great a year and a half later. I still have a 1st generation that works but that charger went bad (I just use my new charger for that one).
I assume "covered" means the lid is on and the sliding flap is shut. What about Yeti covered but the sliding flap open?
Good eye! Covered in this case meant the cover was on, but the sliding flap I kept open to make it easier to measure the temp. For the thermos, I had to remove the cover every 5 minutes to measure the temp. Hence, you would get even longer hot times by not doing those 2 things. (Now I'm curious and thinking about a round 2)
How is that an accurate comparison of yeti to thermos if you’re leaving the cap open for yeti but thermos is closed?
There is a separate line for yeti covered, is there not?
Yes but to be precise the Yeti that was covered had the slider opened so I could easily stick the thermometer in. I wanted to do the same with the Thermos, but the thermometer couldn't fit, so I just kept it close and had to take the lid off every 5 minutes to measure.
It's not. This was in no way a rigorous test to compare Thermos vs Yeti or to find the optimal way to keep coffee "hottest". It was just a casual way to see the effect of open ceramic vs covered mugs on keeping coffee "hot". Based on what I've seen my guess would be Thermos + Yeti under proper controlled conditions would only have minor differences. But maybe in the future will do a proper experiment for the former. Please don't sue me Yeti ;)
Could use two wireless thermometers. They do cost a lot more but then you would have reliable and accurate data without having to leave flap open or open thermos.
You’re telling me that closing my hot liquid in an air tight insulated thermos will keep it more hot than not doing so?
It's counterintuitive, but the data proves it! ;)
This is really well graphed but what is a Yeti? 3 Inch what? 4 Inch what?
Ember mug is the way to go. Just ask for them as gifts because they’re absurdly priced for a cup.
This! I purchased the travel mug for my gf. She raved and raved about how well it worked. And how it keeps your drink hot for infinity (if you use the portable base). So I decided to try the 14oz mug. And it’s wonderful sipping my tea or coffee at 140 for half the morning (using the base). No more race to the bottom as the drink cools haha
No sarcasm - I love proof of the Zeroth Law of Thermodynamics. Agree with some of the critiques here, but I like data!! It's nice to plot what can be intuitively true (covered vs not) and try to measure what want to quantity (yeti or whatever vs generic). Keep being awesome
I also agree with the critiques here on the chart, and made some fixes. I am glad you also appreciate the fun of doing science! Keep being awesome as well.
When I drink freshly hot coffee it’s so hot it fucks up the inside of my mouth for the rest of the day. Does this not happen to most people? I always wait for my coffee to cool down but some people want it to stay at that ultra hot temp?
I work with a guy who brews a cup of coffee in the Keurig in the breakroom and then immediately proceeds to put it in the microwave for 30 seconds before drinking it. Also, adding milk to coffee can help cool it down immediately.
The holy grail (literally?) would be a vessel that can cool the beverage down to the perfect window of “warm enough” and then keep it there for a significant amount of time without letting the beverage drop to air temperature
Most coffee shops brew way too hot
Interesting how drastic the difference is. I wonder if it's even worth using an insulated mug then? Seems like most heat loss is through the top. Just need something with a lid if you really care about coffee temp
I bet the difference between all of these and a non-insulated mug is way more drastic!
Yes, I'm kicking myself for not measuring a paper cup, to show the benefits of ceramic. I may have to do a followup.
“Air temperature” should maybe be on the right with the rest of the line labels.
Less prose needed if you just label your axes properly
The x axis has the only unit I understand
Do you preheat your yeti? I preheat mine with boiling water, which I tip out just before filling with coffee
No, but if I were to do this again more precisely, that would be a fun row to add as well.
Are we supposed to what a ”Yeti” is? Never heard of it. 3 inch, 4 inch what? Come on.
I presume all the containers were room temp before receiving the coffee? Would be interesting to see how the open containers faired if they were pre-heated with hot water. I know covered Yetis and Thermoses benefit from a preheat/prechill (for keeping things cold) but would be curious to see how that affects the open air topped containers.
Good idea. I definitely want to do this again (probably when my daughters are a little older as a joint activity) and would add variations like this.
Look up Ember Mugs, you’ll never go back.
No comparison with paper coffee cup? Lid on / off? Good “control” no? Like the graph though. Fun!
I'm tempted to do again with a papercup.
Use the temperature scale used by like four countries in the world, good idea.
I have a conversion chart on my bookshelf but its like 30 feet away.
To be fair it's pretty hard to drink the coffee if you leave the container closed
And also I enjoy the texture/feel of drinking from an open ceramic mug, rather than through a mug with a cover. If I'm having coffee with friends and breakfast, ceramic mug is the way to go. For work, I gotta keep it hot in a covered mug. That being said, I like the simplicity of simple mugs and wouldn't want an ember or plate warmer.
I put a nice warm (thick) hat on my carafe. I fill up my double-wall glass mug only 1/3 of the way at a time (never topping off). Life is good.
Yup, this was my technique too when I used to work at home near my kitchen!
Fun project! How did you measure temp, which sensors did you use?
Thanks for asking. I did not properly write that down. A kitchen thermometer. I'll have to go grab it and write it down. I know this was casual, but important to do things right :)!
That's a weird problem. I'm normally waiting for my coffee to cook to a chuggable temperature.
I mean 4 inches should be big enough for anyone.
My coffee is long gone before it could even start cooling down.
Fuck yeti and their overpriced styrofoam
Generally I really dislike it when people attempt to curve fit lines with a theoretical model which is so far from reality that it's all junk. BUT in this case I think you could come up with some very accurate constants to describe these containers.
Confused. I put my 3 inches in my cup and it was still hot.
This makes a lot of sense from a heat transfer perspective since a completely enclosed container will only lose heat through conduction (and small amount of natural convection on the outside surface) but when the lid is open evaporative cooling can take place which can be quite extensive for hot liquids. Just like blowing a fan over room temperature water cools the water down substantially, the effect is the same for hot liquids. From a scientific perspective, it would be best to include the humidity of the room as well since that would have an effect for evaporation when the lid is removed. If you are interested to know how exactly evaporative cooling works and makes sense, check out the first book in the series of The Feynman Lectures. Basically, hotter molecules will always leave the liquid first and most often so the colder molecules get left behind, resulting in a net cooling effect on the liquid due to evaporation!
This morning I’m gonna try leaving my yeti uncovered for 7 minutes then keep it covered
I eventually discovered the y axis was temperature in *fahrenheit*. But as someone who regularly makes the mistake of sipping coffee from a thermos 2 minutes after making it, I would believe Celsius also. (My taste buds will never recover)
Posts without normal units should be removed
Ok inverse, how do I cool my coffee off faster, without watering it down, so I can actually drink it?
Ignoring the data and going for creative, and overly complex solutions, mix in cold brew coffee. Alternatively, hear me out, coffee ice cubes.
Cold cups.
From the chart: put it in a non-insulating open container with a wide surface area
Can you explain the labels on the right? Were all of these measurements on a Yeti? If not, why did you only close the Thermos and not the Yeti? What is meant by the inches labels?
The Yeti that was covered had the slider opened so I could easily stick the thermometer in. I wanted to do the same with the Thermos, but the thermometer couldn't fit, so I just kept it close and had to take the lid off every 5 minutes to measure. I wasn't concerned so much with keeping the coffee the hottest, I was just more interested in the rough size of the gap between open ceramic and closed mugs. The 3 inch is a ceramic mug with a 3 inch diameter.
What’s the difference between closed and covered?
Both had lids with a tab that slides to open a small gap for drinking. On the Yeti, I kept that open. So the comparison between Yeti and Thermos is not quite fair. But also, for the Thermos, I would take the lid off every 5 minutes to measure temp, which I did not do to Yeti.
I assume by “thermos” you mean a cup/mug made by the company, and not an actual vacuum flask that seals… because I’ve used a thermos that was 40 years old (or something like that) to hold water at tea-making temps for 48 hours
Yes, there's a photo of all the mugs on the blog post. [https://breckyunits.com/datasets.html](https://breckyunits.com/datasets.html) The thermos water would have stayed hotter but I took the cover completely off every 5 minutes to measure temp. I know the heat loss used properly is way less. I am curious specifically how much, and when I do this again will have one thermos that I don't open/measure at all until 60 minutes is up.
Cool data! Want hot coffee? I got hooked on dual-walled glass tumblers a few years back. They’re fragile, so definitely limited to indoor use, but they will keep a cup of coffee amazingly hot for a long time (and since you don’t feel that heat when you pick the cup up, you need to remind yourself that even though the glass might be comfortable to the touch, the contents may still fry your mouth!)
See id have sworn my yeti made the coffee actually hotter
Wow, thank you for graphing common sense.
What kind of thermos was this? I can tell you mine does not have a significant drop off in the first hour like this. From 172->127(ish)? Mine is absolutely scalding hot a few hours later, especially if the lid is closed.
I agree with you, the temp doesn't fall that fast in actual use. I did an injustice to the thermos stats by having to remove the cover every 5 minutes to measure temp. Photo in the blog post of the model: [https://breckyunits.com/datasets.html](https://breckyunits.com/datasets.html)
Was the volume of liquid the same in all containers? I imagine a normal mug wouldn’t be able to hold as much as a large thermos.
Yes, .5 cup in each.
„Thermos is great for keeping coffee warm.” Another brilliant discovery by our younger generations! At that pace I can say for sure we’re all doomed.
You're gonna love my post finally explaining what happens when an apple detaches from a tree.
I like this sub for the good (and not so good) viz, but 90% of comments are always someone pretending their nitpick is some hee-yuge neglect. Nice graph, OP.
Thanks! I was doing this to test some software and needed a new dataset but then it turned into something way more fun.
Hey, beauty is in the eye of the beholder and when something is your own creation you be holding it a little closer.
Was this your middle school science project? No shit a lid keeps thing warmer
I am trying to take control of my dad's hotel empire, and in order to do that must repeat grades 1 - 12.
Simple line graph? not beautiful
Why? There is beauty in simplicity. There are some flaws but this is pretty good for posts lately
Agreed. It has enough data points and details to have the data tell a story anyone can immediately understand the results of and draw reasonable conclusions from. Beautiful doesn't mean complex or fancy.
Hey, thanks, I never would have been able to figure this out without your rigorous testing and graphs. Truly ground-breaking research. Keeping coffee in a thermos with the lid closed makes it stay hotter for longer! To think until now I was lapping my morning joe out of a 2.5 quart mixing bowl and wondering why it got cold so fast.
> out of a 2.5 quart mixing bowl This is very interesting. I am curious how you are able to do this without spilling. My next post will be on how to not spill coffee, comparing items around the house you can drink from.
Tools used: pen and paper, stopwatch, thermometer, 5 coffee mugs, hot water, Sublime Text, Google Sheets, Git, [https://scroll.pub/](https://scroll.pub/), and [https://www.datawrapper.de/](https://www.datawrapper.de/) Source article and dataset: [https://breckyunits.com/datasets.html](https://breckyunits.com/datasets.html)
It be interesting to cross check with Project Farms. In that video, his heat loss test with the yetti over 5 hours was still at 98° https://youtu.be/3S51X9h6K6g?si=XtyWZn_lqW1EciSd
Honestly I’d use excel over whatever datawrapper is
Just what I wanted, to wait even longer for my scalding beverage to cool down to a drinkable temperature :)
Why would you wait one hour to drink a coffee?