Kimoto is known as a traditional shubo method and was developed after bodaimoto. This sake brewing method involves heavy mixing of the mash with the use of oar-like paddles, producing lactic acid that protects against spoilage.
Over the past hundred years, the sake community has always had a strong relationship with the past and the future. Although there have been technological advancements in producing sake in recent years, the sake I enjoy with my friends is essentially made using similar techniques that have been used for about five hundred years, and kimoto is among those methods.
If you are curious about what kimoto sake brewing is, the characteristics of kimoto sake, and more, this post is for you. So, let’s start!
What is Kimoto?
Kimoto is an authentic method for brewing sake, developed around the 1700s. It uses the laborious yamaoroshi method with kai (oar-like paddles) for heavy mash-mixing. The mixing takes more than 10 years or up to 12 hours.
This traditional brewing method introduces a natural lactic acid for sterilizing the rice, yeast, water, and koji mixture. These bacteria start the entire sake-making process and make it easier for the yeast to promote alcoholic fermentation.
In order for brewers to keep track of the time and stay in rhythm, they play traditional songs. Low temperatures are essential to prevent spoilage. The mash is complete after 25-30 days. Since kimoto sake is very difficult to make, it makes up around 1% of all sake.
What Does Kimoto Sake Taste Like?
Kimoto sake is usually earthy, funky, and rich. This kimoto method gives a depth of flavor to the sake. It can also deliver a gamey flavor. And sweetness and acidity are elevated.
I love serving kimoto sake cold because of the great taste it offers. But anyone can also enjoy it warm. Plus, it is very food-friendly. So, I have no problem choosing which food will complement the sake’s earthy, sweet, and acidic tastes.
Whenever I host a gathering at home, my foreign friends quickly fall in love with kimoto sake. Of course, they love it more with their favorite Japanese foods.
What are the Different Characteristics of Kimoto Sake?
Below are the kimoto’s two different characteristics:
Propagate Lactic Acid Bacteria
The first main characteristic of kimoto is to propagate lactic acid bacteria. These bacteria is found in the shubo in the brewery. This method builds an inhospitable environment for unfavorable bacteria.
Since the kimoto method depends on natural bacteria, it takes labor and time to complete the process. That is why industrial lactic acid is applied directly to the fermentation starter through the sokujo method to shorten the shubo production period.
Involve Yamaoroshi (Pole-Grinding)
The rice in the shubo is mashed or ground for proper dissolution. This process aims to prevent the propagation of other germs as much as possible before the rice is dissolved.
Traditionally, brewers have to wait longer for the rice to finally dissolve since rice polishing technology is less developed than today. This introduces a higher risk of unfavorable bacteria contamination before the rice is completely dissolved.
Kimoto Fermentation Starter Process
Brewers have to work and wait almost a month to complete the kimoto brewing method.
Day 1: Ikemeshi, Shikomi, and Temoto
In ikemeshi, also known as buried rice, after cooling the steamed rice, it is wrapped in straw mats or placed in half-cut (hangiri) tubs. Then, it is covered with more straw mats, keeping the temperature and produce hard-core rice.
In shikomi (mashing), cooled steamed rice, water, and koji are mixed into shallow tubs.
In temoto, also known as hand-mixing, after absorbing lots of water, the mash is mixed using hands or a wood board. This helps make the rice soft with the necessary consistency.
Day 2 to 3: Motosuri and Motoyose
In motosuri (pole-grinding), after 12 hours from the shikomi stage, the mash is ground using wooden poles (kai).
The brewers only rub the rice, not completely mash it, to encourage rice dissolution.
In motoyose, also known as putting together the separated mash, the two tubs’ contents are put together. This step is repeated the next day and the day after until all portions are put into the shubo tank.
Day 3 to 4: Utase
During this stage, the mash is mixed for around 3 to 4 days to promote koji. As the rice dissolves, sugar is produced, while nitrate-reducing bacteria generate nitrous acid to prevent unfavorable bacteria propagation.
Day 5 to 12: Hatsudaki to Maedaki-kikan
Shubo is stirred in a hot water container called daki-daru to increase the temperature. It also helps promote rice dissolution. Lactic acid bacteria then feed on sugar as well as multiply to ensure lactic acid production.
The synergy between the lactic acid and nitrate-reducing bacteria kills off wild yeast. Later, nitrate-reducing bacteria die as well due to more lactic acid production.
Day 13: Fukure
After the extermination of nitrate-reducing bacteria, amino acids, and sugar, sake yeast is produced. Ambient or cultivated yeast can be added. As the yeast starts to multiple and promote carbon dioxide production, the tank content rises, known as swelling (fukure).
Day 14 to 18: Wakitsuki and Wakitsuki-yasumi
In wakitsuki, also known as the start of full-blown fermentation), more carbon dioxide gas is generated. This makes the shubo surface bubbly. The temperature is also raised to promote more yeast proagation. The yeast produces alcohol that kills off the lactic acid bacteria.
In Wakitsuki-yasumi, also known as the end of the heating stage, when the fermentation and yeast activity becomes vigorous, heat is produced by yeast. Then, nukumi-tori daki, where heating to 30° takes place, is applied.
Day 19: Wake
The yeast finds it difficult to be active as the temperature keeps rising. That is why shubo needs to be cooled to keep the yeast activity.
Day 21: Karashi
During conditioning period known as karashi, the shubo will have to mature for 1 to 2 weeks. With the maturation period, the yeast activity is adjusted to suit the major fermentation.
The kimoto method is responsible for creating sake’s depth of flavor, and modern sake-making techniques cannot match it. Using natural lactic acid results in excellent, very pure, and powerful yeast that produces mild acidity and complex flavor.
Now that you know how your favorite kimoto sake is prepared, you will surely appreciate every gulp of it.