What's the Shelf-life of Vermouth (if you keep it in the fridge?)
I use VacuVin on both types of vermouth, and find they last a good four months (for dry) to six months (for sweet) before the flavor starts to change.
I hoarded a bottle of Antica Formula, the most awesome sweet vermouth I've ever tried -- better even than Vya or Punt e Mes -- so tasty I only drank it straight. It seemed too good and rare to mix into cocktails. (I can't get it in Massachusetts; a fellow drinks writer kindly shipped me a bottle from New York.) It lasted that way for a year, had clearly suffered a little by the end, but not spoiled.
Spoilage is not generally a problem for me; I find lots of ways to use vermouth: cocktails, highballs, cooking, straight on the rocks with a twist.
Well there are a lot of opinions on this one... but the consensus is that although Vermouth is a fortified wine it does eventually oxidize and will either go "bad" or more likely the flavor will become "dull" which affects the flavors in your cocktails. Sweet vermouth will generally "last" longer than dry vermouth.
I agree with what Jay at the Oh gosh blog has to say:
"I just wish smaller, more easily finished bottles were readily available... a lot of supermarkets only sell 1 litre bottles of vermouth, and given how long these often sit in peoples alcohol cabinets, that makes for a lot of imperfect vermouth…"
Here is a previous chowhound forum on the subject:
in a post by Robert Hess in The Spirit World blog he says:
"It is widely accepted however that once a bottle of vermouth has been opened, it is probably best to store it in the refrigerator if you are not expecting to use it within a day’s time. Myself, I’ve found that a bottle of premium vermouth, once opened and left in the cupboard for a month or more, essentially just turns into a “lesser” vermouth, instead of being totally unacceptable. So you don’t have to be “too” concerned, but none-the-less, I keep my vermouth in the fridge."
You can watch this video of Robert Hess making a Martini and he reiterates the above @ ~ 7:18 into the video.
It does go slightly bad...you wouldn't want to toss the vermouth out...but you could tell the difference between the older bottle and the newer one it would be like a premium brand versus a lesser brand...always try to use fresh vermouth or keep it in the refrigerator.
@ Oh Gosh The poster, Jay, did an experiment with opened "older" bottles of vermouth vs. new bottles. to sum up (but read the article anyway):
"Overall then, confirmation of knowledge I already practise. Dry vermouth is relatively unstable, so should be used quickly and/or refrigerated once opened. Sweet vermouth fairs better, but does still dull so shouldn’t be kept around too long. Given the low-cost of vermouth it is thankfully affordable to keep bottle around for 3-6 months and dispose of once faded."
From the book "Aperitif..." p.72:
"Once opened, recap tightly. Vermouth [i believe they are referring to sweet vermouth here] will keep up to one year stored in a cool dark place or refrigerated. Noilly-Prat [and here dry vermouth] recommends storing their product in the refrigerator for up to six months."
About.com related to cooking with Vermouth:
"vermouth will keep without going stale for at least two months"
Well I hope this helps.
Check out the Robert Hess video & post as well as the "Oh Gosh" Links.
As is frequently yhe case, it depends. How new when put in the fridge? How much head space in the bottle? Did you use a preservation system, like WineSavor or even a vacu-vin? generally speaking, a new bottle put in the fridge just after opening will kep for 6 months or so. That's why I usually buy half bottles(which all good makers of Vermouth make). If I get into the mood for martinis or manhattans or negronis, I'll open a whole bottle, but then I'm committed to drinking heavily for the next month or two. What a shame. anything left when a bottle starts losing freshness gets used to poach fish, which it does quite nicely.