- The answer to the question ? How long does Cognac last? is a matter of quality, not safety, assuming proper storage conditions - when properly stored, a bottle of Cognac has an indefinite shelf life, even after it has been opened.
To maximize the shelf life of Cognac for quality purposes, store in a cool dry area away from direct heat or sunlight; keep tightly closed when not in use.
Once a bottle of Cognac is opened, the contents may begin to evaporate slowly and some flavor may be lost over time, but the Cognac will remain safe to consume if it has been stored properly.
How to tell if Cognac has gone bad? The shelf life of Cognac is indefinite, but if Cognac develops an off odor, flavor or appearance, it should be discarded for quality purposes.
Sources: For details about data sources used for food storage information, please click here