Direct reducing sugar

Direct reducing sugar (also called "chokuto" in Japanese) refers to a sugar that has a free aldehyde or ketone group in its molecule and therefore shows reducing properties. Such sugars also play an important role in sake. In sake, the amount of direct reducing sugar is generally expressed as glucose equivalent, and it contributes to the sweetness and flavor of the sake. The direct reducing sugar content of commercially available sake is generally around 3 to 4%, and within this range the sweetness is pleasant. Because direct reducing sugar affects the flavor and mouthfeel of sake, controlling it during the brewing process is important.