Yeast & Fermentation

Can you brew beer with sake yeast? Yes, because sake yeast, known in Japanese as kobo, belongs to the species Saccharomyces cerevisiae, just like many beer yeasts. It's related to the yeast that ferments top-fermented beers. Top-fermented means the yeast collects at the top after fermentation and works at around 18 to 22 degrees Celsius, while lager yeast ferments at the bottom at around 8 to 12 degrees Celsius.

Sake yeasts are known for fruity aromas, such as banana and pear, produced mainly by the compound isoamyl acetate. Since 1906, the Brewing Society of Japan has distributed certified strains, known as Kyokai yeasts, to breweries across the country. Many houses also maintain their own proprietary strains.

Kizakura brewery in Fushimi reportedly produces a beer using the same yeast it uses for its sake. It's called Kyoto Beer. How it tastes depends on the strain, since the yeast contributes aromas that hops don't.

Kyoto Brewing, by contrast, reportedly uses a Belgian yeast as its house strain. Belgian yeasts produce spicy and fruity aromas reminiscent of clove or pear, making them well suited to beers that aren't meant to taste like lager.

The difference in fermentation is also significant. In sake production, the conversion of starch to sugar and sugar to alcohol happens simultaneously in the same tank, whereas in beer brewing the two steps are kept separate. That's why sake yeast is only a guest in beer brewing, and the brewer must understand its behavior precisely.