White Koji is made using a mutated strain of black koji mold, Aspergillus kawachii. Like black koji, it produces a significant amount of citric acid. Despite its name, it is brown in color, named because it is "whiter than its black koji predecessor." It is easier to handle than black koji and has become the mainstream choice for shochu production.
Recently, sake made with white koji has gained attention. One of its unique features is the flavor transformation due to citric acid, resulting in a distinct, refreshing citrus-like acidity.