Rice Preparation

Question 1

What are the 3 things the brewer is looking to achieve during rice preparation?

Answer 1

1. Reduce levels of proteins, lipids, vitamins, and minerals - which can lead to faster fermentation, texture, and acidity that is not usually desired.
2. Adjust the amount and distribution of moisture within the grain (helping koji mold growth and grains to break up/dissolve during fermentation).
3. Gelatinize the starch to facilitate the break down of starch to sugar by the koji enzymes.

Question 2

If a robust and flavorsome style of sake is sought what type of rice should be used?

Answer 2

Rice that is less polished. Also the water absorption rate does not need to be as precise. This will allow for faster ferments at higher temperatures and higher levels of koji activity.

Question 3

How long does it take to polish rice to 50%

Answer 3

At least 45 hours.

Question 4

Why is rice washed?

Answer 4

To remove any remaining nuka or rice bran, which is made up of undesirable components.

Question 5

What is the general moisture level for rise when soaking?

Answer 5

30 - 35%.

Question 6

What are the two main reasons it is not good to over-soak rice?

Answer 6

1. If rice is to be used for koji, the mold will grow too quickly without producing the appropriate levels of koji enzymes.
2. If used in moromi/fermentation, the rice will break up too quickly, resulting in yeast having access to high levels of sugar, causing them to ferment too quickly.

Question 7

What are the two purposes of steaming rice?

Answer 7

1. Sterilizes the rice
2. Alters the molecular structure of the starch molecules.
   Bonus: Also increases moisture level of rice to about 40%