As an expert sommelier and brewer, I can confidently say that absinthe does not technically go bad in the traditional sense. Due to its high alcohol content, typically ranging from 45% to 74%, absinthe is a highly potent spirit that acts as a natural preservative. The alcohol acts as a deterrent to bacterial growth and prevents the growth of mold or other spoilage organisms. So, even if you have an open bottle of absinthe for years, you won't find any mold growing inside.
However, while absinthe may not spoil, it can undergo changes over time that affect its flavor and fragrance. This is mainly due to oxidation, a process that occurs when the spirit comes into contact with oxygen. Oxidation can lead to the gradual breakdown of various compounds in the absinthe, resulting in a loss of aromatic complexity and a weakening of its overall flavor profile.
The effects of oxidation on absinthe can vary depending on factors such as the quality of the spirit, the storage conditions, and the length of time since it was opened. Absinthe stored in a bottle with a tight seal and kept in a cool, dark place will generally experience slower oxidation compared to a bottle that is repeatedly opened and exposed to air.
I have personally witnessed the effects of oxidation on absinthe during my years of working in the industry. I have tasted absinthe that has been stored for several years, and while it may still be drinkable, the once vibrant and aromatic notes have significantly diminished. The herbal and floral complexities that make absinthe so unique can fade over time, resulting in a less vibrant and nuanced drinking experience.
To mitigate the effects of oxidation, it is recommended to consume absinthe within a reasonable time frame after opening. This timeframe can vary depending on the specific brand and bottle, but generally speaking, it is best to consume absinthe within a year or two of opening to ensure optimal flavor and fragrance.
While absinthe does not spoil in the traditional sense, it can undergo changes over time due to oxidation. The high alcohol content acts as a natural preservative, preventing the growth of mold or spoilage organisms. However, the flavor and fragrance of absinthe can weaken over time, resulting in a less vibrant drinking experience. Therefore, it is best to consume absinthe within a reasonable time frame after opening to fully appreciate its unique qualities.