1. What is koji?
Koji is cultured koji-mold on steamed rice, barley or other grains. Koji is widely used for making traditional Japanese fermented foods including sake, shochu, miso, soy sauce, and vinegar. Koji provides enzymes that break down the starch and protein of the grains, as well as flavor compounds of fermented food. Different kind of koji-mold is used for different fermented food, since required enzymes and flavor compounds are different, such as koji for miso, koji for sake, etc.
2. What is the difference between sake koji and shochu (Japanese distilled liquor) koji?
Koji is made by culturing koji mold on steamed rice, barley, or other grains. Sake is made using a yellow koji mold*1. Shochu is made using black*2 or white koji*3. Shochu koji, from black or white koji mold, produces a lot of citric acid that is different from yellow sake koji. It produces acid-resitance amylase. This citric acid makes the shubo and moromi (the main fermenting mash) acidic and prevents contamination by harmful bacteria, thus permitting safe fermentation.
*1 As an exception, red koji or Rhizopus, instead of yellow koji is used from sake-making.
*2 Some shochu is made from rice with ancient production methods using yellow koji mold.
*3 The name of black and yellow koji mold comes from the color of their spores.
3. How many types of yeast are used to make alcohol?
To produce alcohol, manufactures select the yeast that matches the type of alcohol they want to make, the raw materials, and the fermenting conditions. For example, sake is fermented by sake yeast, beer by beer yeast. You can't make beer successfully if you try to brew it using sake yeast. In addition, there are specific yeasts to make each type of sake, such as ginjyoshu and jyunmaishu.
And then, there are native yeasts (inherited within specific families) and yeasts developed and held by regional research institutes, as well as the yeasts available on the market.
Sometimes, one identical yeast strain has several different names. Therefore, it is not possible to state precisely how many types of alcohol-producing yeasts exist.
4. What is Jozo-alcohol?
Jozo-alcohol is alcohol added in the process of sake making, and in making other liqueurs, such as Umeshu. Jozo-alcohol is made by fermenting molasses, or starch from grains or cassava, and subjecting the wort or mash to continuous distillation. Jozo-alcohol is carefully refined so that it will not affect the flavor of the beverages it is added to.
5. What is makkolli?
Makkolli is alcoholic beverage traditionally made in Korea. Its name means 'coarsely filtered'. Makkolli resembles Japanese sake in that it is made from rice, wheat, and koji make with rice and/or wheat. However, the type of mold used, the method to make koji, the degree of the rice polishing, the preparation methods of mash, fermenting temperature, and the cultivation of fermentation are different, so the flavor is different from that of Japanese sake. The flavor of Makkolli resembles that of doburoku (unfiltered, homemade sake) in Japan.