How Long Do Opened Bottles Last?

How long an opened bottle lasts comes down mainly to alcohol content, sugar content and how much air reaches the liquid. Spirits around 40% ABV are effectively impossible for microorganisms to grow in. Liqueurs are protected by the combination of alcohol and sugar. Anything wine-based, meaning vermouth, sherry and port, oxidises much like an ordinary wine, just more slowly.

So this guide splits the home bar into three groups: what lasts for years, what lasts for months and what should be used within days.

Vodka, gin, whisky, rum, tequila, brandy and other spirits do not go bad. An unopened bottle does not keep developing either, so a whisky that sat in the cupboard for ten years is exactly as old as when it was bottled.

Once opened, slow oxidation sets in and some aromatics evaporate. In a full bottle you will barely notice. It is when the bottle is less than about a third full that the air inside starts to change the flavour noticeably over a year or two, especially for aromatic whiskies. A nearly empty bottle of something good is a fine reason to finish it.

Store bottles upright, in the dark, at room temperature. Upright because high-proof spirit slowly breaks down a cork, dark because sunlight fades both colour and aroma.

Most liqueurs are perfectly fine for a year or more after opening. Sugar and alcohol keep them stable, but fresh fruity aromatics, as in berry and citrus liqueurs, fade with time.

Cream liqueurs are the exception that needs a bit more attention. The makers of the big brands state they last about two years from production, opened or not, and that refrigeration is not required as long as the bottle is kept cool. Egg liqueurs such as advocaat keep for a shorter time once opened; follow the label.

Cocktail bitters like Angostura are so high in alcohol that they effectively last forever. The only change is that the aroma slowly fades.

This is where most home bartenders make their most common mistake. Vermouth is wine, fortified with extra alcohol to around 15 to 18% ABV and flavoured with botanicals. The fortification slows oxidation but does not stop it.

Put opened vermouth in the fridge. It is at its best for roughly the first month and perfectly usable for two to three months. At room temperature it goes noticeably flat within a few weeks: the aroma fades and the taste drifts toward sour and dull. A Martini or Manhattan made with old vermouth does not taste wrong, but it tastes worse than it should.

The same logic applies to other wine-based bottles. Fino and manzanilla are the most delicate and should be finished within about a week of opening, like a white wine. Sweet and oxidative styles such as oloroso, tawny port and madeira last considerably longer.

Buy half bottles if you mix rarely. A 375ml that is finished in a month makes better drinks than a litre that stands open for half a year.

Homemade 1:1 simple syrup keeps for about a month in the fridge. Rich syrup, two parts sugar to one part water, lasts longer because the higher sugar content leaves less free water for mould and yeast. A splash of vodka in the bottle extends it further.

Syrups with fruit, herbs or spices are more delicate than plain simple syrup. Throw out any syrup that has turned cloudy, smells yeasty or has mould on the surface. Store-bought syrups follow the label, but count on a couple of months after opening.

Fresh lemon and lime juice is best the same day. It already changes within the first few hours, and after a day in the fridge much of the brightness is gone. Squeeze a little at a time rather than a big batch for the week.

Pasteurised bottled juice keeps a few days in the fridge after opening, per the package. Tonic and soda lose carbonation quickly in an opened bottle. Small bottles that are finished in one serving put more fizz in the glass than a big bottle opened five times.

In My Bar you can mark when you opened a bottle and whether it lives at room temperature or in the fridge. Shookd works out a use-by date from the type of bottle and warns you when vermouth, syrups or mixers are getting close. Spirits and bitters get no date, because they do not need one.