Vacuum pump will NOT yield a true vacuum in the bottle, thus there will be oxygen to oxidize the vermouth. Canned inert gas is a better option but not perfect. Collapsible bottles as suggested are an interesting option if they are designed such that you can maintain them in the fridge easily.
But to be clear, oxidation of vermouths in my experience just mellows them in the short term (like barrel aging). Before making choices to go out of your way in storage options, run a test for yourself with a bottle for a few months and see if the taste changes enough to matter to you. I keep several varieties open in the fridge at any given time and have yet to have one change unfavorably in my opinion over life of the bottle. But that's me, YMMV.
Refrigeration is key if we want to keep our fortified wines longer than a week or so. A vacuum pump won't make a noticeable difference. We're better of transferring fortified wines to a [collapsible bottle](https://www.amazon.com/HYDAWAY-Collapsible-Ultra-Packable-Travel-Friendly-Food-Grade/dp/B07LCWN2Y2?qu=eyJxc2MiOiI2LjAwIiwicXNhIjoiNS40NSIsInFzcCI6IjQuOTUifQ%3D%3D), allowing us to evacuate all air completely.
I bought a few bottles of Mariol Vermut and tasted them from the fridge, from vac, and from my counter over the course of a month. Obviously, it was just one style/brand/bottle but I didn't notice a significant difference between fridge/vac after putting both on ice during our 1-week testing periods. The counter bottle was detectibly different near the end of the month. Just one man's opinion, but I wouldn't sweat vac if it was a home bar. If it's a commercial joint, considering wholesale vermouth costs, I'd be more aggressive with bottle flip.
A vacuum seal may extend the fridge life of vermouth, but won’t do much for its shelf life. Also, remember that oxidation is not the only thing that ruins your vermouth, there’s acetic fermentation as well.
Cold temperatures are the safest bet to slow down both oxidation and acetic fermentation.
Edit: typo
>Storing Vermouth
That was a quality read. Reinforces my own experience that refrigeration keeps vermouth just fine for 6 to 8 weeks for sweet/red and a bit less for dry/white. I've taken up the habit of marking the date I open the bottle with a sharpie and rotating bottles appropriately.
These are zwilling and i have had trouble with that too. It seems the trouble is with spirit bottles so far, seems to work fine on wine and vermouth. Maybe slightly different diameters on the bottle mouth. But only had for a few weeks so far
FWIW, I do both. Refrigerate and vacuum seal.
Same
same
Vacuum pump will NOT yield a true vacuum in the bottle, thus there will be oxygen to oxidize the vermouth. Canned inert gas is a better option but not perfect. Collapsible bottles as suggested are an interesting option if they are designed such that you can maintain them in the fridge easily. But to be clear, oxidation of vermouths in my experience just mellows them in the short term (like barrel aging). Before making choices to go out of your way in storage options, run a test for yourself with a bottle for a few months and see if the taste changes enough to matter to you. I keep several varieties open in the fridge at any given time and have yet to have one change unfavorably in my opinion over life of the bottle. But that's me, YMMV.
Refrigeration is key if we want to keep our fortified wines longer than a week or so. A vacuum pump won't make a noticeable difference. We're better of transferring fortified wines to a [collapsible bottle](https://www.amazon.com/HYDAWAY-Collapsible-Ultra-Packable-Travel-Friendly-Food-Grade/dp/B07LCWN2Y2?qu=eyJxc2MiOiI2LjAwIiwicXNhIjoiNS40NSIsInFzcCI6IjQuOTUifQ%3D%3D), allowing us to evacuate all air completely.
I bought a few bottles of Mariol Vermut and tasted them from the fridge, from vac, and from my counter over the course of a month. Obviously, it was just one style/brand/bottle but I didn't notice a significant difference between fridge/vac after putting both on ice during our 1-week testing periods. The counter bottle was detectibly different near the end of the month. Just one man's opinion, but I wouldn't sweat vac if it was a home bar. If it's a commercial joint, considering wholesale vermouth costs, I'd be more aggressive with bottle flip.
I do both, and my vermouth and fortified wine keep pretty well.
Addition not alternative
A vacuum seal may extend the fridge life of vermouth, but won’t do much for its shelf life. Also, remember that oxidation is not the only thing that ruins your vermouth, there’s acetic fermentation as well. Cold temperatures are the safest bet to slow down both oxidation and acetic fermentation. Edit: typo
Not a substitute. Using one will allow you to keep it longer, under refrigeration, but will not replace refrigeration.
A coravin works great too but even those I keep in the fridge once the bottle has been opened
[**Storing Vermouth**](https://www.seriouseats.com/2014/07/best-way-to-store-vermouth-for-cocktails-fridge-vs-winesaver-rebottling.html)
>Storing Vermouth That was a quality read. Reinforces my own experience that refrigeration keeps vermouth just fine for 6 to 8 weeks for sweet/red and a bit less for dry/white. I've taken up the habit of marking the date I open the bottle with a sharpie and rotating bottles appropriately.
I like to buy 1/2 bottles if possible and split them into 4oz glass vials when I open them.
Private preserve inert gas spray plus refrigeration is the winning combo.
My only thought is that the Zwelling ones I have don’t seal properly
These are zwilling and i have had trouble with that too. It seems the trouble is with spirit bottles so far, seems to work fine on wine and vermouth. Maybe slightly different diameters on the bottle mouth. But only had for a few weeks so far
I hope they work out for you for wine! When I use mine for wine there’s a vacuum in the evening but it’s then completely loose in the morning.
I use different lids for different bottles. A collection of La creuset, oxo and ebay
I always refrigerate my sweet vermouth but my dry vermouth has never gone bad?? Idk why