Bottle and glass of whiskey next to barrel
Why You Can't Keep Your Best Whiskey In Its Original Bottle
Once you open a bottle of whiskey, time is limited before its flavor starts to deteriorate due to oxidation. However, transferring it to a smaller bottle helps delay the process.
Storing it in a smaller bottle reduces the amount of space for air in the bottle and, thus, the amount of air contacting the whiskey, limiting oxidation and extending its life.
Use a glass bottle or decanter to avoid imparting other flavors from materials like metal or plastic into your whiskey, and ensure it has a tight-fitting cap so air doesn’t get in.
That said, even if you transfer your whiskey into a bottle that’s smaller than the original, it’d only reduce oxidation. It’s pretty much impossible to halt the process entirely.
To enjoy the flavor of your whiskey to the fullest, many recommend consuming an open bottle within two months. However, some suggest it may retain its flavor for up to six months.