Sake is crafted by fermenting rice, rice koji, and water into alcohol. However, since rice grains contain no sugar on their own, rice koji is used to break down the starch in the rice into sugars, which are then fermented into alcohol using yeast.
A pure, concentrated culture
of this yeast is called
" Shubo (Yeast Starter)."
Also known as "moto," shubo literally translates to "mother of sake" and plays an indispensable role in brewing. The way this yeast starter is prepared directly influences the flavor profile of the final sake.
The Kimoto Method...
is a traditional Japanese brewing technique passed down through generations used to cultivate the yeast starter and brew sake.
Water, koji, and steamed rice are divided into shallow wooden tubs called hangiri-oke, where artisans carefully mash the steamed rice and koji into a paste using wooden poles called kaburagai.
This mashing process is called "Yama-oroshi"
and is a distinctive feature of Kimoto brewing.
Through Yama-oroshi, natural lactic acid bacteria from the environment are leveraged, creating a protected environment for yeast to multiply.
Lactic acid bacteria play a vital role in preventing spoilage in the yeast starter.
While wild lactic acid bacteria yield a rustic, rich flavor,
the process requires around one month for the yeast starter to mature.
Yamahai is a method of preparing the yeast starter without the laborious "Yama-oroshi" mashing step. Its full formal name is Yama-oroshi Haishi Moto-jikomi (literally, "yeast starter made by discontinuing Yama-oroshi").
Developed during the Meiji period, brewers discovered that enzymes from koji could naturally dissolve rice grains without manual mashing.
By adjusting the order in which ingredients are added, the Yamahai method allows natural lactic acid bacteria to thrive through koji enzymatic activity, generating the necessary lactic acid. This technique also requires about one month to prepare the yeast starter.
Because Yamahai yeast starters grow in symbiosis with lactic acid bacteria,
they yield sake with deep, rich umami flavors.
While traditional Kimoto and Yamahai methods yield rich, full-flavored sake, they also carry a higher risk of spoilage during production.
The innovation that solved this challenge is
"Sokujo-moto (Fast-Developing Starter)."
By adding commercial lactic acid directly at the yeast starter stage, brewers create a stable acidic environment that prevents wild bacteria contamination, significantly reducing the risk of spoilage.
Without the need to wait for lactic acid bacteria to grow naturally, the starter matures in about 15 days.
Because Sokujo-style starters contain fewer wild microorganisms and no by-products from lactic acid bacteria, they tend to produce highly aromatic, light, and crisp sake.
If a label does not specify "Kimoto" or "Yamahai," it is likely brewed using "Sokujo-moto," which has become the primary method in modern sake production.
Sake Brewing Tips
Order of importance in sake brewing.
This traditional proverb ranks koji rice as paramount, followed by the starter (moto), and finally main fermentation mash (tsukuri).
Sake is brewed through "Multiple Parallel Fermentation," where saccharification and alcohol fermentation occur simultaneously in the same vessel.
This unique process is rare worldwide, requiring intricate steps and high technical skill.
We invite you to explore different
varieties at your local shop!
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Now That You Know, Let's Choose
