The name of sake changes in detail depending on the ingredients and how it is made. First of all, it is roughly classified into Junmai-Shu, Ginjo-Shu, Jozo-Shu, etc. according to the rice, rice polishing ratio, and the presence or absence of brewed alcohol as ingredients. This time, I would like to go a little further than these large categories. Have you ever seen something like “Yamahai” on the label of sake? This is one of the classifications by yeast starter. This time, I would like to take a look at this yeast starter and its classification.
・What is yeast starter (Shubo)?
A yeast starter is a culture of yeast required for fermentation of the”moromi” and is the source of alcoholic fermentation when making sake. There are three types of yeast starter, which are Sokujomoto, Kimoto, and Yamahaimoto, respectively. Currently, Sokujomoto is mainly used while brewing sake, but sake using Kimoto and Yamahaimoto is also manufactured, and it is stated on the label of the sake. So what are the characteristics and tastes of each?
Sokujomoto is made by artificially adding lactic acid to suppress the growth of germs other than yeast. As a result, fast-brewed yeast will be ready in about two weeks, so sake brewing will proceed speedily. It has a high fragrance and a smooth taste, so it is suitable for making Ginjo-Shu.
Kimoto-zukuri is characterized by waiting for lactic acid bacteria present in the air to produce lactic acid, rather than artificially adding lactic acid that suppresses the growth of germs. In order to incorporate lactic acid bacteria into a raw material that is a mixture of rice, water, and yeast, the raw material must be mixed with a propeller. In the old days, it was done manually using a large paddle. This process should be done at midnight during the intense cold season to prevent the growth of germs. The sake produced with such extremely hard labor is “Kimoto-zukuri” sake. The taste is wonderful because it took a lot of time and effort. It is characterized by its richness and solid taste, yet refreshing.
The heavy labor mixing work that was in the Kimoto process mentioned above is called “Yamaoroshi”. Yamahaimoto is a name that comes from “abolishing (hai)” this “Yamaoroshi”. Instead of Yamaoroshi work, they put in an enzyme called “water yeast” that is generated by immersing the yeast in water. The characteristic of this sake is that it is rich, tasty, and has a solid taste.
The above is the classification by yeast starter. If you want to go one step further and choose your favorite sake, please pay attention to how it is prepared.