The reason why each sake tastes different is because of the rice and water used, the environment and temperature it is made in, and yeast. This time, we’ll be talking about yeast, something crucial in sake making.
Yeast in Sake
Yeast is a microorganism that cannot be seen by the naked eye. Its job is to ferment, and it can be found all around us. For sake, yeast is added to koji so that the rice’s sugar is converted to alcohol and carbon dioxide. This is called ethanol fermentation. When soy sauce and sake is made, yeast is heavily relied on. It used to be thought that koji made yeast. During the Meiji period (1888-1912), beer brewing came to Japan and gave insight on how yeast was involved. Yeast is called “kobo” in Japanese.
Yeast Used Around the World
There are many types of yeast, but the most common is used in bread. The dough releases carbon dioxide to rise. As you can see, sake isn’t the only type of food that requires yeast. Various fermented foods are made with it. When it comes to alcohol, there is sake yeast, dried beer yeast, and wine yeast.
Interesting Types of Yeasts in Sake
Sake wouldn’t taste as delicious without yeast. Now, if you pay careful attention, you’ll find out that some sake uses interesting yeasts.
-Sekizen/Junmai Hiyaoroshi Cosmos Yeast
This sake is brewed with flowers from the fall, cosmoses. It has the best characteristics of a hiyaoroshi sake: mellowed, a matured tanginess, well-rounded, and a smooth after taste.
-Amabuki/Junmai Ginjo Sunflower Yeast
Sunflowers are flowers of the summer. It makes Amabuki a perfect dry sake for the hot season with its refreshing taste.
-Amabuki/Koi Suru Banana Junmai Ginjo Nama
Bananas, a fruit that adds a subtle sweetness, are used in this sake. When you drink it, you’ll taste the sweetness and smell the fruity aroma. This is a limited-edition sake, but there is also one called Junmai Daiginjo Banana Kobo Nama that is not.
–Rosé no Yukidoke
Yeast that gives a red color is used, hence its name: rosé like rosé wine. The flavor will remind you of strawberries with a perfect balance of sweetness and sourness. This sake is still running through trials, but there are breweries that make other sake using red-colored yeast on the market.
Sake characteristics are different based on the kind of yeast that is used. Check it out the next time you pick up a sake bottle.