First things people ask about sake is how long it can be kept, how to keep it, and what temperature to drink it at. In short, sake generally keeps well for about one year before deteriorating.
After opening,if kept sealed and refrigerated, it will maintain quality for a few weeks before losing flavour. In general, most premium sakes are better drunk chilled, and cheaper sakes drunk warmed. However, there are exceptions! Certain sakes are designed to be drunk warm, this should be labelled on the bottle. Sake should also not be drunk too chilled as this might mask its favours.