Sake is a traditional Japanese alcoholic beverage obtained by fermenting rice. It is often referred to as Japanese rice wine, although the process of making sake more closely resembles the brewing process, where starch is converted into sugars and then fermented into alcohol. Making sake involves the fermentation of specially prepared rice, which is first polished to remove the outer layer and then milled, soaked and cooked. A kōji fungus (Aspergillus oryzae) is added to the cooked rice to initiate the fermentation process, converting the rice starch into sugars, which are then fermented by yeast, producing alcohol. Sake has a wide range of flavours and aromas, which can vary depending on the ingredients used, the region of production, the fermentation process and how it is served. It can vary in flavour notes, from sweet and fruity to dry and earthy. The serving temperature can also vary, from chilled sake to room temperature to a heated drink, which further influences the experience of flavour and aroma.