Pasteurize twice to maintain the quality of sake stable
In traditional sake process, there are still few yeasts and enzyme in sake, and may contaminant by “Hiochi Bacteria (火落菌)” at the storage or bottling stage. That’s why most sake will pasteurize twice before storage stage or bottling stage. The pasteurize mothed in sake process called “Hiire (火入れ)”.
The Hiire method was recorded in the Muromachi period (AD. 1336~1573) and became the standard procession in Edo period. We all know the pasteurization mothed was established in 1864, but the Japanese sake breweries already know this method more than 500 years ago.
The Hirre method is keeping the temperature in 62℃ to 68℃ and making yeast, enzyme, and Hiochi bacteria denature. Alcohol and flavor compounds will escape with the heating stage, that why sake after Hiire method will lose some delicate flavor.
Some sake breweries will make one label with “Nama” and “Hiire” different version. If you see one label with “Nama” and “Hiire” version, don’t miss this chance to compare the difference of flavor.