Unlike some wines, distilled spirits do not age or mature in the bottle. Your unopened bottle of scotch that has been on the shelf for 20 years will taste the same as it did the day it was bottled. However, once you open a bottle, some liquors may go bad, while others may lose their character over months or years.
The freshness of the liquor in your bar depends on its alcohol content, sugar, and other ingredients. For example, a high-proof schnapps will last longer than one with less alcohol but the same amount of sugar. Cream and fruit liqueurs are also prone to spoiling after several months. Hard liquors like vodka and whiskey have an indefinite shelf life, even when opened, though you may notice that the flavor begins to fade after a year or so.
Hard Liquors
The base liquors (brandy, gin, rum, tequila, vodka, and whiskey) are the most shelf-stable distilled spirits. These average 40 percent alcohol by volume (80 proof—though some are stronger) and typically do not contain added sugars, so you can store these bottles for a very long time.
Unopened, these hard liquors have an indefinite shelf life.
Once opened, they will lose certain flavor qualities over a few years but will never really spoil.
The exceptions are flavored spirits, which may contain sugar and additives that lower their shelf life. If you have a flavored vodka, rum, or tequila below 80 proof, it may contain sugar. Also, look for lower-proof flavored brandies and whiskies that have “liqueur” on the label. Treat all of these like liqueurs.
You may notice a diminished character, particularly in the aroma and subtle taste nuances of complex spirits like brandy, gin, whiskey, and aged rums or tequila. Since vodka is relatively neutral in flavor, it is the least susceptible to flavor loss. Instead of wasting them, these older liquors are best served in mixed drinks rather than consumed straight.
Liqueurs and Cordials
The shelf life of a liqueur (e.g., schnapps, amaretto, and triple sec) is more temperamental. These spirits contain sugar and other ingredients that can spoil, and some are more problematic than others. Generally, you’ll want to discard open bottles after about 18 months.
For example, liqueurs with a high concentration of sugar (e.g., crème liqueurs) will deteriorate faster. Some may include preservatives to combat spoilage, and you might find these listed on the label. On the flip side, a higher-proof liqueur contains more alcohol, which should protect it for a little longer than lower-proof liqueurs.
Liqueurs that contain dairy, cream, or egg should be consumed as soon as possible. Even in unopened bottles, these liqueurs may spoil and be undrinkable after a year and a half or more. Some of the more sensitive liqueurs include an expiration date on the bottle.
There are a few general rules regarding the shelf life of liqueurs:
Most opened (and well-sealed) liqueurs should last for six months to a year (or even longer), depending on the alcohol content and preservatives.
Once you notice sugar crystallizing on the bottom, discoloration, curdling, or other changes, throw the bottle away.
Do a smell and (small) taste test before drinking any questionable liqueurs.
Fortified Wines
The shelf life of opened fortified wines like dry and sweet vermouth is longer than that of regular wines, but it is not as long as that of liquor. If stored for too long, it will become musty and stale, so keep an open bottle of vermouth for just two to three months. Some people prefer to store vermouth in the refrigerator, while others say that it is unnecessary.
Nonalcoholic Spirits
Alcohol is an excellent preservative, but it is not present in nonalcoholic spirits. This modern sub-market of the cocktail world has a different set of shelf life standards. The formulations and ingredients are widely varied, so each brand is different. On average, an opened bottle will remain good for six to 12 weeks. Most do not need to be refrigerated, and you can typically find storage recommendations on the label.
Nonalcoholic Mixers
Follow the recommended expiration date on the labels of all juices, bottled cocktails, and similar mixers. Refrigerate these after opening.
Consume sodas and sparkling waters immediately after opening the bottle or shortly thereafter. There’s no point in adding soda to your drink when there’s no fizz left. If you find yourself wasting a lot of soda when making only a few drinks, buy packs of miniature bottles. One small bottle of club soda can usually mix two or three cocktails.
Liquor Storage Tips
While liquor can stay good for a considerable amount of time, there are specific steps you can take to ensure you get the freshest taste out of any bottle. The most important is to avoid leaving open bottles too long: for the best flavor, plan on drinking liqueurs within eight months and hard liquors within a year or two.
Store liquor bottles upright. While it is traditional to store wine on its side when it is sealed with a cork, liquor bottles should always stand upright. This prevents leaks from screw caps, and there is the possibility that the alcohol will eat away at cork enclosures and taint your liquor.
Keep opened bottles tightly sealed. Use the original cap, a replacement cork, or a wine stopper that removes the air from the bottle.
Never store liquor with speed pourers unless you are using them during a party. Even the best designs allow air to get inside the bottle and will quickly deteriorate the alcohol’s quality.
Avoid exposure to extreme heat or cold. Keep your liquor cabinet away from an exterior wall and heat vents.
Avoid bright, direct light. Consider storing liquor bottles behind tinted glass if window light is prevalent in your bar.
Generally, it is unnecessary to refrigerate cream liqueurs, but many people do because it can prolong their freshness.
When in doubt, pour the liquor in question into a glass. If it does not look, smell, or taste right, it is probably best to throw it out.