Sake Journey –酒母の巻 visiting mother of sake-

in Sake world, there is an expression;
"First Koji, second Moto, and the last, brewing",
to show the most important processes of sake making.
the before the last post I had introduced how Koji is made,
today I would like to talk about "Moto = Shubo", yeast starter,
and literally means, the mother of Sake.

日本酒づくりの大切な工程を示す表現に、
「一麹、二酛(もと)、三造り」というのがあります。
前々回に紹介した麹づくりの次に重要な「酛＝酒母」
酒のお母さんについて今日はお話しようと思います。

In a small cylindrical tank, mixing water, finished koji rice,
lactic acid, a concentration of pure yeast cells, and plain steamed white rice.
the reason why we add lactic acid is to stay away from bad bacteria floating in the air,
because sake is an open-tank fermentation unlike wine and beer,
which fermentation usually takes place in a closed-off container.

小さな円筒形のタンクの中に、水、麹米、乳酸、酵母菌、そして蒸したお米を入れます。

乳酸を入れるのは、解放上のタンクの上から、雑菌が入り込むのを防ぐため。

（ワインやビールは密封した中で発酵が行われるそうです）

The temperature of the tank is measured at all time and controlled
to keep specific and stable environment for enzymes in the completed koji
to produce enough sugar from the startch of rice, as well as for the yeast to grow and increase the number of the cells that can reach 100 million cells in one teaspoon is developed after two weeks or so!
(the second photo is how we traditionally control the temperature; to put ice in the long tall tube to cool down, and to put hot water in the bucket looking "Dakidaru" to warm up the Shubo)
so I got to have a look at increasing yeast cells:

タンクの中の温度は常に一定の温度に保たれ、麹菌の酵素がお米のでんぷん質を
糖化する活動と、酵母菌が増殖する活動を助けます。
御所野蔵は全てコンピューターでタンクの温度を制御されていますが、
二枚目の写真は、本社蔵のもの。細長い筒に氷を入れて酒母を冷やし、
取手付きのバケツのような「暖気樽（だきだる）」にお湯を入れて温める時に使います。
約二週間の間に酵母菌の数は、小さじ一杯で一億にまで増えるそう！
ということで、酵母菌の増殖する様子を顕微鏡で覗かせてもらいました：

The photo above, is Shubo after 15days. the white circle objects are the yeast cells.
I had compared with the one after 6days (forgive me i have no photo...),
the 6th day one had only two pieces of yeast cells found,
whereas this nearly finished batch is full of them.

上の写真は15日目の酒母。お米の粒の様に白くて丸いのが酵母菌です。
6日目のものは（写真がなくて失礼…）二粒くらいしか見つけられなかったのに対し
15日目、完成間近のものは明らかに酵母菌でいっぱいです。

As the Shubo develops, all kinds of lovely smells arise in the Shubo room.
These aromas will vary greatly depending on the type of sake; like Ginjo sake, Shubo often has burst of fruity essences, such as apples, bananas, pineapples and strawberries.
I want to live in this room...

酒母が完成するにつれて、酒母室はお酒のいい香りがひろがります。
酒の酒類によって香りの要素は異なりますが、吟醸酒の酒母でいえば、
林檎や、バナナや、パイナップル、苺を思わせる、溢れんばかりの果実の匂い。
この部屋に暮らしたい。