The ultimate hiire sake is born. Hiire is a technique to deactivate enzymes and yeast by submerging sake in hot water so that the sake quality will not be damaged even if it is stored for a long period. The quality of sake usually changes after hiire and before hiire, but by adding carbon dioxide microbubbles to the sake, the hi-ire time has been dramatically shortened. The result is the ultimate hi-iru sake, with a quality almost identical to that of nama-shu, but with little change in quality over a long period of storage. The fresh flavor of nama-shu and the elegant and calm quality of 20-30% sake are truly superb.