Yeast – Home Brew Sake

A moto before kimoto? – Bodaisen to Bodaimoto

Before getting with this article I would like to urge you to consider donating to help Japan in this time of tragedy. Three outstanding organizations which will ensure your donations will be used well are:

https://www.sakesamurai.jp/donation.html

https://www.mercycorps.org/

https://www.redcross.org/

OK, back to the article:

We often here about the three types of moto or seed mash. There is the currently most used moto type, sokujo-moto, the next most common, Yamahai-moto and the moto which was king before that, kimoto. But, before these there was another type of moto, one that was used as late as 1925 under the name Mizumoto. This moto was bodai-moto and was developed by the monks at the Bodaisen Shoreki Ji Buddhist temple.

The monks studied the techniques used in both Japan and China. They developed their method some time in or before the 14^th century. A brewing diary, “Goshu no Nikki,” describes the two step method and later starting in 1478 as chronicled by the “Tamon-in Nikki” the three step method was developed and used. Taken together these describe how the method for making Bodaisen had transformed from a single mash sake brewing to one that used a starter culture from previous good mashes to one with a purpose made starter mash, bodai-moto, added to the main ferment and the progressions from including two and then three additions to the moromi.

Continue reading “A moto before kimoto? – Bodaisen to Bodaimoto”

To foam or not to foam, that is a question of the yeast?

Sake brewers have long used the appearance of the foam to tell the stages of the moromi’s progress (fermentation progress). The named stages are as follows:

Foam Stage	English Translation	Aprox. Timing
suji-awa (筋泡)	Muscle Foam	day 2-3 of Moromi
mizu-awa (水泡)	Water Foam
iwa-awa (岩泡)	Rock Foam
taka-awa (高泡)	High Foam	Day ~10 of Moromi
ochi-awa (落泡)	Falling Foam
tama-awa (玉泡)	Ball Foam
ji (地)	Land or Ground

Pictures for each of these stages as seen through the foam can be seen at the Daishichi’s site.

Continue reading “To foam or not to foam, that is a question of the yeast?”

How Sake is Brewed

Brief introduction to how sake is brewed.

Sake is brewed in a strung out process that can take quite a long time but none of the steps are particularly difficult. In the traditional method, brewing sake starts with the rice and its milling. The objective is to remove the outer layers of the rice which cause sake to be less stable and to have harsher flavors. These layers contain the bran and the highest concentrations of oils, fatty acids, proteins and minerals like magnesium and iron. Table rice (white rice) is generally milled to around 93% of its original size. Sakemai (Sake Rice) is usually milled somewhere between this for futsu-shu (table sake) and 35% for the most refined Daiginjo. Removing these components leads to a more stable and refined sake.

Once the rice has been milled to the proper level we need to steam the rice. We used steamed rice both for making koji and to directly add to the brew. In order to steam the rice properly we need to first wash the milled rice to remove the outer layer of rice flower, talc or whatever may be on the rice. After a good washing the rice is soaked to absorb the needed amount of water for proper steaming. This amounts to about 30% by weight. The higher the milling rate the faster the rice will absorb the desired amount of water. Kurabito (brewery people) working with the most highly polished (Milled) rice often use a stopwatch to time the soaking period so the rice does not take on too much moisture. Here the goal to get enough moisture into the rice so that the steaming process gelatinizes the rice by heating the water already there. If the rice has too much moisture it will become soggy / mushy during the steaming process and will not form a nice home for koji. Continue reading “How Sake is Brewed”

More Sake Yeast

This article contains information on the yeasts that the Japanese Central Brewers Union collects and distributes.

Last week I wrote about sake yeast but the post got to be longer than I intended so I cut it short. I left off a little of the more commonly mentioned information about the yeast strains collected and distributed by the Central Brewers Union.

You may recall from the last post that back in the early 1900s the Central Brewers Union in Japan started collecting pure strains from particularly good batches of sake. The Central Brewers Union then made these pure strains available to all breweries. These pure strains where given numeric designations. So far there are from #1 to #16 and the low foaming strains. Many breweries now use these yeast strains but many also use of private strains. Continue reading “More Sake Yeast”

Sake Yeasts

Discusses yeast, sake yeast and what yeast need to do a good job fermenting.

Yeast: a single cell fungus whose activities have been known to man for far longer than we have known about yeast itself. We have evidence of yeast being used as far back as four thousand years ago in Egypt. They used yeast for both baking and brewing. Wine was also present in this period.

In 1857 Louis Pasteur proved that fermentation was the results of living yeast rather than a chemical reaction. In this work, Pasteur showed that as oxygen is added the growth of the cell count increases and fermentation slows. Not only did this show the significant of yeast but also its two distinct modes of operation: the aerobic and the anaerobic. In the aerobic mode, yeast reproduce by budding, a process of a child cell being created and split off from the parent cell. The anaerobic mode proceeds with little to no growth in the number of cells but with increased alcohol and CO₂ production. Alcohol and CO₂ are produced in equal amounts based on the following formula:

C₆H₁₂O₆ -> 2 C₂H₅OH + 2 CO_{2 Continue reading “Sake Yeasts”}

Sake Yeast Mash – The Moto

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”

Basic Brewing Radio goes to Sake One!

A two part video of SakeOne, the kura and sake.

Basic Brewing Radio, on a trip to Portland, stopped by SakeOne and filmed their tour at the local kura (Sake Brewery). The tour is presented in two parts:

Part One, Jenifer introduces us to the sake brewery. She discusses the water, milling the rice and making the koji.

Continue reading “Basic Brewing Radio goes to Sake One!”

Sake basic ingredients

Sake has four basic ingredients: rice, koji, yeast and water. Each play an important part in producing the taste, aroma and appearance. Each are discussed and how they come together to form the sake we love.

Sake is made with four ingredients: rice, koji, yeast and water. All, except the koji, are familiar to most people. Koji is a mold culture grown on rice in the case of Sake. The mold is Aspergillus oryzae. It forms a white fluffy coating over the rice and excretes alpha-amylase which converts the rice starch into sugar. This is the primary function of koji in brewing sake; to provide enough alpha-amylase to convert most of the starch provided by the rice to sugar. Other compounds produced by the koji contribute to the final taste.

Once the koji converts the starches from the rice to sugar, yeast converts the sugars to alcohol. Beyond this major contribution the yeast also produces other compounds that contribute to the final taste and aroma of the sake. These two processes, conversion of starch to sugar and conversion of sugar to alcohol, proceed at the same time which allows the yeast to produce higher levels of alcohol than is the case in beer and wine. This is not to say that beers and wines can not ferment to the high levels that sake does but that special processes, outside the norm are needed to obtain the same high level normally reached with sake. Continue reading “Sake basic ingredients”