What is sake yeast Kyokai #701?
Sake yeast Kyokai #701 (saccharomyces cerevisiae) is one of the most well-popular yeast strains used for sake brewing in Japan produced by the brewing society of Japan. It was isolated by a sake brewery in Nagano, Japan and started distributing in 1946. It’s particularly used for more earthier styles of sake called Junmai. The “01” indicates that it is a non-foaming version of the #7 strain. Kyokai #701 has good growth in cold temperatures which allows us to produce a lager when used in beer, while producing aromas that common lager yeast strains cannot produce.
How does it differ from beer yeast?
Beer yeasts usually require fermentation temperatures between 50°F – 85°F depending on the style but sake yeasts are commonly fermented between 41°F – 55°F.
Sake yeast #701 in Ginjo 7
In order give the sake yeast a familiar environment, we mashed with steamed calrose rice to give the wort nutrients and proteins from the rice. Due to Ginjo 7 goes through a slow cold fermentation like sake, fermentation time is longer like lagers but produces ale-like fruity esters from the sake yeast resulting in a hybrid product unlike any lagers or ales.