Lactose

Lactose is a disaccharide (a double sugar) composed of galactose and glucose bonded together, found mainly in human breast milk and cow's milk. In sake brewing, sake yeast cannot ferment lactose, so lactose plays no direct role in the brewing process. As a result, it does not affect the taste or flavor of sake. However, it is useful to understand the presence of lactose when considering how sake pairs with dairy products that contain it.