“Sake”, also referred to as “ni-hon-shu” (Japanese rice wine), is made by fermenting rice which has been polished (to remove the bran) to varying ratios. The four necessary components of sake are rice, water, yeast and koji (fungi used to convert starch to sugar). Sake is primarily classified in relation to the level of polishing of the rice grains used, with the lower the percentage indicating a finer grain, and typically is considered of a higher quality. The highest classification is “daiginjo”, indicating that at most 50% of the rice grain remains, followed by "gingo" (60%), "honjozo" (70%) and "futshu-shu" (no minimum). Another important term of classification is “junmai” which relates to a ‘pure’ brewing style, utilizing only the four necessary ingredients in the brewing process. The absence of the “junmai” classification indicates that a percentage of neutral distilled spirit may have been added (to further extract flavours). Generally, sake denoted by "junmai" can be expected to have a more rich and savoury flavour, rather than more subtle, floral flavours.
Sake can either be served warm or cold, dependant both on personal preference, and on the style of sake. For premium sake (with a higher polished grain), signified by the term 'ginjo' or 'daiginjo', it is usually recommended to serve them cold in order to not overpower the sake's light body, and to highlight the subtle aromas and flavours.