Shiroboke (white haze)

Shiroboke refers to the phenomenon in which sake loses clarity during storage and turns cloudy white. It is caused mainly by proteins, formed from koji enzymes (especially saccharifying enzymes) that were denatured by pasteurization, coagulating and settling in the sake. Shiroboke appears in sake after pasteurization and is commonly seen, to varying degrees, in many sakes. It resembles the cloudiness caused by hiochi bacteria (spoilage bacteria), but with shiroboke the cloudiness disappears when the sake is warmed and returns when it is cooled. For this reason, although the cloudiness is visually conspicuous, shiroboke is not considered a particular defect, and some drinkers regard it as part of the character of sake.