[Tell me what you can't ask now!? Series 12] Moromi = Preparation = Making
Moromi-making is the process of transferring the yeast starter into a large tank, adding steamed rice (kakemai), rice malt, and preparation water to promote full-scale alcoholic fermentation. In this article, Nakano Eri will explain "About Moromi = Preparation = Making."

What is moromi making?
The yeast starter is transferred to a large tank, where steamed rice (kakemai), rice malt, and brewing water are added to promote full-scale alcoholic fermentation. The aroma and flavor of the moromi directly reflects its quality. Genshu is made by squeezing and filtering the moromi, while doburoku is made without filtering it.
The "san-moromi" in "ichi-koji, moto, san-tsukuri" refers to this process, and "tsukuri" and "shikomi" are also used interchangeably. Shochu and soy sauce are also called moromi when the ingredients are fermented.
This person will explain

- Toji shop owner/producer Eri Nakano
-
ProfileIn 1995, he opened the Japanese sake bar "Janapese Refined Sake Bar Tojiya" in Tenjinbashisuji, Osaka. He is active in various fields as a sake critic, seminar lecturer, and lyricist.
Three brewing steps, three times over four days, are the standard
To achieve gentle fermentation, the ingredients are not all added at once; instead, steamed rice (kakemai), rice koji, and brewing water are added in three batches over a period of four days, a "three-stage brewing" method that is mainstream in sake brewing. Each stage is referred to by its own unique terminology, which may remind many people that sake brewing is a traditional industry.
It is also in this process that a uniquely Japanese fermentation form known as "multiple parallel fermentation" is observed, in which rice koji converts the starch in the steamed rice into sugar, while at the same time yeast breaks down the sugar to produce alcohol and carbon dioxide.
First wedding, dance, wedding ceremony, wedding ceremony
Adding ingredients at the beginning (first layer) is called "hatsuzoe."
The brewing tank is filled with water, the rice koji is added, and then the yeast starter is transferred from the yeast starter tank. In small breweries, the yeast starter is often poured into a bucket called a "yudame" or "tame," and then carried on the shoulder to the brewing tank, which is also physically demanding work.
On the second day, called “Odori,” no ingredients are added. By waiting, observing, and measuring the yeast growth, important criteria for predicting how the fermentation will proceed from then on can be obtained.
On the third day (second tier), the "nakazoe" is added. Double the amount of ingredients is added as in the first tier. Then on the fourth day (third tier), the "tomezoe" is added. Double the amount of ingredients is added as in the middle tier.
Because the amount of material increases with each tier, many breweries use smaller tanks for the first tier and larger tanks for subsequent tiers.
The amount of each ingredient is different at each stage because adding the entire amount at once would lower the acidity and yeast density of the yeast starter, which could lead to the proliferation of unwanted bacteria. It is believed that healthy fermentation can be achieved by not subjecting the yeast starter to sudden changes and allowing it to adapt to changes in the environment without stress.
Of course, the final result will also change depending on the proportions of yeast starter, rice koji, steamed rice (kakemai), and brewing water. The amounts of each vary depending on the quality of sake you are aiming for, and this is called the "brewing ratio."
Temperature control is also important in this process. In order to maximize the flavor of the rice and bring out the ginjo aroma, and to achieve the desired quality of sake, temperature control is carried out precisely.
How many levels are there?
As far as I know, it is brewed in ten stages.
The ingredients added from the fourth stage onwards vary depending on the sake brewer, and can include rice koji, glutinous rice, enzyme preparations, etc., but when you consider that the yeast that converts sugar into alcohol is killed by the alcohol it has produced at the end of the three-stage brewing process, it seems it is not as simple as just increasing the number of times the ingredients are added.
Over 500 years ago...the technology dates back
The three-stage brewing method allows fermentation to proceed while keeping the yeast alive, resulting in an alcohol content of over 20%, which is rare for brewed alcohol. This method is described in the sake brewing technique book "Goshu no Nikki" from the Muromachi period, when there was no chemistry or microbiology. Even if the sake of the time was low in alcohol, we can be proud of the excellent level of Japanese sake brewing techniques.
Next time: [Tell me what you can't ask now!? Series 13]About the management of moromi
Previous article: [Tell me what you can't ask now!? Series 11]Don't let germs get in your way! ~A sake brewery where germs are not allowed to enter~

Toji shop
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