Dassai Hayata Junmai Daiginjo

In sake production, pasteurization plays a crucial role in deactivating enzymes and yeasts, thereby enhancing its preservation. This technique, known since the end of the Muromachi period (1336-1573) among *toji* (master brewers) as *nizake*, has evolved into the refined method called *hi-ate*, allowing sake to stand as one of the world’s rare preservative-free alcoholic beverages.

At Asahi Shuzo, they employs heat pasteurization despite its high cost. Our process begins by bottling at a low temperature (below 5°C) and then using a hot water shower to heat pasteurize the sake. Immediately following this, we cool it rapidly to mitigate any negative effects of heat on the sake’s flavor.

However, even with the utmost care, heat inevitably impacts the quality of sake. To address this, we’ve introduced micro-bubbled carbon dioxide into the process, which allows pasteurization at 65°C in just 15 seconds while maintaining the sake’s integrity. 

This breakthrough method, patented in 2013 (Patent 2013-008455, Nippon Medical School / Asahi Shuzo Co., Ltd.), began as a collaboration between the late Professor Yasuyoshi Hayata of Meiji University and Asahi Shuzo. After Professor Hayata’s unexpected passing, his work was continued by his student, Assistant Professor Fumiyuki Kobayashi of Nippon Medical School. This innovation was successfully commercialized in 2016.