Sake is a rice wine, made by fermenting rice and water. The Japanese have been brewing Sake for more than 1000 years with the "modern" process refined around 500 years ago. The process of making it is unique, having more similarities with brewing beer than fermenting wine. Much like wine and beer, there are a wide range of different styles of Sake, each with different flavours and characteristics. Some are served chilled and some are best served warm so it is best to research the brand you are buying to make sure you enjoy it fully.