As an expert sommelier and brewer, I can confidently say that unopened bottles of liquor do not expire if stored correctly. Liquor, such as whiskey, vodka, rum, brandy, gin, and tequila, have a relatively low sugar content which means they do not spoil or go bad like perishable food items. However, it is important to note that the flavor and quality of liquor can change over time, especially if it is not stored properly.
When it comes to storing liquor, the key factors to consider are temperature, light, and air exposure. Liquor should be kept in a cool, dark place, away from direct sunlight and extreme temperature fluctuations. Heat and light can degrade the quality of the liquor, causing changes in flavor and aroma. Therefore, it is best to store bottles away from windows or other sources of light.
Additionally, liquor should be tightly sealed to minimize air exposure. Oxygen can interact with the alcohol molecules and lead to oxidation, which can affect the taste and aroma of the liquor. This is especially true for spirits that have a higher sugar content, such as liqueurs, which are more prone to spoilage. However, base liquors like whiskey, vodka, rum, brandy, gin, and tequila usually do not have a high enough sugar content to kickstart oxidation.
I have personally experienced the effects of improper storage on liquor. Once, I left a bottle of whiskey on a shelf near a window, and over time, the sunlight caused the color to fade and the taste to become dull. It was a valuable lesson for me to always store liquor in a cool, dark place to maintain its quality.
It is worth mentioning that some factors, such as the type of bottle closure, can also impact the longevity of a liquor. Cork closures can allow small amounts of oxygen to enter the bottle over time, potentially affecting the flavor. However, most spirits are bottled with screw caps or synthetic corks, which provide a better seal and minimize air exposure.
To summarize, unopened bottles of liquor can remain in storage indefinitely without a significant impact on their flavor and potency if stored in the proper conditions. Storing liquor in a cool, dark place, away from direct sunlight and extreme temperature fluctuations, and ensuring a tight seal will help maintain the quality of the liquor over time. While liquor does not technically expire, it is essential to be mindful of storage conditions to enjoy the best possible taste and experience.