When bourbon sits out, it undergoes a series of changes that can affect its taste, aroma, and appearance. As a sommelier and brewer, I have observed these changes firsthand and can provide you with a detailed explanation of what happens when bourbon is left exposed to the air.
One of the first things to occur when bourbon is left out is evaporation. Alcohol has a lower boiling point than water, so it tends to evaporate more quickly. This means that over time, the alcohol content of the bourbon may decrease slightly. This evaporation process can also lead to changes in the flavor profile of the bourbon, as some of the more volatile compounds are lost.
As the bourbon continues to sit out, another interesting phenomenon takes place. Fatty acids and other compounds, which are normally dissolved in the liquid, can begin to precipitate out. This can result in the bourbon becoming cloudy or hazy in appearance. The presence of these precipitates can also impact the texture and mouthfeel of the bourbon, giving it a slightly thicker or heavier consistency.
Furthermore, as the bourbon is exposed to air, it may interact with oxygen, leading to oxidation. This oxidation process can have both positive and negative effects on the bourbon. On one hand, it can help mellow out harsh flavors and contribute to the development of more complex and nuanced aromas. On the other hand, excessive oxidation can lead to a loss of freshness and vibrancy in the bourbon, resulting in a less desirable drinking experience.
In addition to these chemical changes, there are also potential environmental factors to consider. For example, if the bourbon is left out in a warm or humid environment, it may be more prone to spoilage or bacterial growth. This can lead to off-flavors and off-putting aromas in the bourbon. Therefore, it is generally recommended to store bourbon in a cool, dark place to minimize the risk of these environmental influences.
To summarize the changes that occur when bourbon sits out:
– Evaporation of alcohol: The alcohol content may decrease slightly over time.
– Precipitation of fatty acids and other compounds: This can result in a cloudy appearance and impact the texture of the bourbon.
– Oxidation: Can contribute to flavor development but excessive oxidation can lead to a loss of freshness.
– Environmental factors: Warm or humid conditions can increase the risk of spoilage and off-flavors.
It's worth noting that the extent and rate of these changes can vary depending on factors such as the specific bourbon, the length of time it is exposed, and the environmental conditions. Ultimately, the best way to preserve the quality of bourbon is to store it properly in a sealed bottle, away from direct sunlight and extreme temperatures.