Longevity: Tequila doesn't expire but can alter in taste once opened, particularly when the bottle is about 25% full.
Añejo tequilas really should be sipped neat, immediately after meal in a very copita or snifter and https://socialrus.com/story17374891/5-tips-about-gran-centenario-tequila-extra-anejo-you-can-use-today