Fermentation Starter (Shubo/Moto)

Question 1

What is the purpose of the Shubo?

Answer 1

Create an acidic environment using lactic acid so that the fermentation yeast can develop

Question 2

How long does a Shubo take to complete?

Answer 2

Sokujo-Moto: 14 days

Kimoto/Yamahai: 28 Days

Question 3

Why is temperature control important for the Shubo?

Answer 3

• To ensure that the yeast are able to multiply at a suitable pace
• To ensure that the yeast do not outpace the starch to sugar conversion carried out by the koji mould enzymes & run out of food

Question 4

Name the 4 advantages of Sokujo-moto

Answer 4

1. Quicker. 14 days instead of 28 days
2. More control, in particular acidity
3. Less risk. No need to rely on bacteria to create lactic acid
4. Purer flavour profile with less umami

Question 5

Name 3 methods to control temperature of the Shubo

Answer 5

1. Daki
2. Pipes
3. Jacket

Question 6

What’s the ideal temperature range for Sokujo-moto?

Answer 6

20-25°C

A good temperature for enzyme extraction & ideal for yeast multiplication.

Question 7

What is the technique of paddling the shubo in the Kimoto method?

Answer 7

Yama-oroshi

Speeds up the breaking up of the rice & increases the amount of contact between the rice starch & koji enzymes.

Question 8

What is the initial fermentation temperature of Kimoto/Yamahai method?

Answer 8

6-7°C

To ensure that only the right kinds of bacteria develop.

Question 8

When is yeast added for Kimoto/Yamahai method?

Answer 8

14 days after start

Question 9

Name 4 reasons for using Kimoto/Yamahai

Answer 9

1. Create interesting flavours & add complexity
2. Richer flavours
3. Higher acidity
4. Especially in Yamahai & some Kimoto, complex nutty & caramel flavours develop due to exposure to oxygen

Question 10

What is the % of koji used in a shubo?

Answer 10

30-33%