Discusses the main fermentation stage of the sake brewing process, moromi.
Once san-dan-jikomi is complete and the final addition has been made we enter into moromi. Moromi starts the day after the final addition, which is tomezoe. It lasts until fermentation is almost complete. This can take anywhere from 2 weeks to about a month.
The time needed for moromi is based on both temperature and koji characteristics. In particular the characteristic diastatic power the koji can muster at the moromi temperature. The yeast work faster at the low temperatures of moromi than do the koji enzymes.
At the end of the moto the alcohol content was anywhere from about 5% to 10%. With the san-dan-jikomi additions the concentration of alcohol was also cut in the same way as the yeast and acid. However, as some yeast has been reproducing some have been producing alcohol. So by the start of moromi we have regained much of the alcohol concentration we had at the end of the moto. Continue reading “The Main Ferment – Moromi”
This article looks at the three types of Sake yeast mashes, also known as moto and shubo. The differences between these three moto are examined.
Moto (元), Shubo (酒母), Yeast mash are all names for the Sake yeast starter. In this article I will only use the term “moto” but the three can be used interchangeably. Moto is where the number of yeast cells is increased to the needed level. The moto is used to inoculate the main sake fermentation, the Moromi (諸味). To build the moto we start with rice (米), koji (麹) and yeast (酵母). These three ingredients along with water were the only ones used for moto originally. The method to produce this original moto is known as Kimoto. It features a vigorous mixing, taking many hours, to produce a puree of the ingredients. It was thought this vigorous mixing, called Yama-Oroshi, was needed for the ingredients to properly work together.
In 1909 a modification to the Kimoto method was developed. The modification was to drop the vigorous mixing. As it turned out, the mixing was not really needed. The modified process was called Yama-Oroshi haishi moto or Yamahai moto for short. Continue reading “Sake Yeast Mash – The Moto”