Sake is a fermented rice beverage made from polished rice, water, yeast, koji mold and, sometimes, brewer’s alcohol.
A common misconception is that sake is a rice wine; in fact, sake has more in common with beer than any other alcoholic beverage. Sake and beer are made from steeped grains brewed and fermented with yeast.
Where sake differs from beer is that sake rice does not have easily accessible sugars for fermentation. To solve this problem, brewers use Koji Mold, rice inoculated with a fermentation culture called Aspergillus Oryzae. Aspergillus oryzae is a key ingredient in many Japanese staples like soya sauce, miso and mirin.
The Koji Mold breaks down the starch of the rice into sugars, and then those sugars are ready to be fermented with yeasts. So unlike beer, sake undergoes parallel fermentations: koji mold (starch to sugar) and yeast (sugar to alcohol).
After fermentation, the rice is pressed and typically filtered, pasteurised and diluted with water. Once bottled and released, sake lasts for 6-18 months. Once opened, sake should be drunk within 1-2 weeks. You can expect a noticeable decline after the first week.
There are many classifications and styles of sake depending on the rice polishing ratio, the use of brewer’s alcohol and production methods; we will explore these in future blogs.