Main Fermentation (Moromi)

Question 1

Name the 3 main aims of the moromi

Answer 1

1. Avoid contamination & fermentation stopping early
2. Achieve correct balance of the parallel fermentation. (Starch to sugar by koji enzymes & sugar to alcohol by yeast)
3. Achieve desired aromas & textures for the style of sake

Question 2

List the ratio of the ingredients for the moromi

Answer 2

1. Rice 80 parts
2. Koji 20 parts
3. Water 130 parts

Question 3

Describe Sandan-Jikomi

Answer 3

1. Day 1: 1st addition (Hatsu-Zoe). Shubo is transferred to larger tank with steamed rice, koji & water. 1/6 of tank. 12-15°C
2. Day 2: Day off (Odori). Nothing added. Allow yeast to multiply. Slight rise in temperature
3. Day 3: Middle addition (Naka-zoe). Double that of the 1st day addition of steamed rice, koji & water. Tank is now 3/6. Temperature lowered to final fermentation temperature of 6-10°C.
4. Day 4: Final addition (Tomoe-zoe). Remainder of steamed rice, koji & water added. Full tank). Temperature lowered to final fermentation temperature of 6-10°C.

Question 4

What is the temperature & length of fermentation for most sakes?

Answer 4

12-18°C & 21-28 days

Question 5

What is the temperature & length of fermentation for Ginjo sakes?

Answer 5

8-12°C & 30-35 days

Question 6

Name 2 methods to control temperature in Moromi

Answer 6

1. Traditional way: Wrap mats around tank. Insert ice in the space between mat & tank to cool fermentation
2. Modern way: Jackets that wrap around tank or heat exchangers submerged in tank. Change in temperature by circulating hot or cold water.

Question 7

What is the ideal fermentation temperature needed for rich Junmai style?

Answer 7

16-18°C

Question 8

What is the ideal fermentation temperature needed for Daiginjo style?

Answer 8

8-12°C

Question 9

How do brewers end fermentation?

Answer 9

By lowering temperature to 3-5°C to stop all yeast activity

Question 10

What is the purpose of the 4th addition?

Answer 10

• It is a technique used to control the level of sweetness in a sake
• Addition is made towards the end of fermentation of aruten sakes

Question 11

What are the 3 components of the 4th addition?

Answer 11

1. Water
2. Steamed rice
3. Small amounts of dextrins

• Dextrin is created by adding koji enzymes to a mix of steamed rice & water
• The enzymes rapidly convert starch to sugar & some starch fragments as dextirins