Kōji

Question 1

What is kōji?

Answer 1

Steamed rice (or barley or other types of grain) inoculated with kōji-kin fungus.

Question 2

What does kōji do?

Answer 2

It creates enzymes that convert rice starch into fermentable sugar. Kōji also produces other enzymes that break down protein and produces amino acids and peptides.

Question 3

what are the three categories of kōji-kin?

Answer 3

1. Ki-kōjo-kin -yellow
2. Shiro-kōji-kin - white
3. Kuro-kōji-kin - black

Question 4

Which type of kōji-kin is used primarily for sake?

Answer 4

Ki-kōji-kin

Question 5

What are the two types of tane-kōji?

Answer 5

Granulated and powdered

Question 6

Granulated tane-kōji is most frequently used for what type of sake?

Answer 6

Ginjo

Question 7

How long does it take to make koji?

Answer 7

40-48 hours.

Question 8

About how frequently is the temperature checked during koji making?

Answer 8

2 hours, day and night

Question 9

Describe so-haze

Answer 9

The koji spore covers the entire rice grain sending many hyphae growing into the kernel.

Question 10

Describe tsuki-haze

Answer 10

The koji spores grow in a lightly spotted pattern over the rice grain with fewer hyphae growing into the kernel.

Question 11

Which style has a lower vitamin and fatty acid content, so-haze or tsuki-haze?

Answer 11

Tsuki-haze

Question 12

Which style dissolves the rice well and promotes strong fermentation.

So-haze or tsuki-haze?

Answer 12

So-haze

Question 13

Tsuki-haze results in sake that is fuller-bodied.

T or F

Answer 13

False

Question 14

During koji making, what is created besides glucose?

Answer 14

vitamins, amino acids, peptides, malic acid, succinic acid.

Question 15

List the seven steps of the Koji making process.

Answer 15

1. Bringing in
2. Spread seed
3. Re-breaking up
4. Mounding
5. Middle Work
6. Final Work
7. Sending Out

Question 16

During what hours does Bringing In occur?

Answer 16

0 hours

Question 17

During what hours does Spread Seed occur?

Answer 17

hours 2-3

Question 18

During what hours does Re-breaking Up occur?

Answer 18

hours 10-12

Question 19

During what hours does Mounding occur?

Answer 19

hours 20-23

Question 20

During what hours does Middle Work occur?

Answer 20

hours 30-33

Question 21

During what hours does Final Work occur?

Answer 21

hours 36-38

Question 22

During what hours does Sending Our occur?

Answer 22

hours 44-48

Question 23

During Koji propagation, what other flavour-influencing components aside from glucose are created?

Answer 23

vitamins, amino acids, pepties, malic acid, succinic acid, and others.

Question 24

Describe Futa-koji

Answer 24

The koji-innoculated rice is moved to futa, smaller containes resembling lids or trays. The separating allows the humidity and temperatures of the rice to become more even, The brewers can shift the locations and layers everty 3 hours or so. This method handles 1.5 kg to 2.5 kg of rice. Used for higher grade, expensive sake.

Question 25

Describe Hako-Koji

Answer 25

Box koji - This method is commonly used for a wider range of sake. It is a simplified version of Futa-Koji. The brewer puts the rice into large boxes, futa, split with a divider that can slide from side to side to control the release of temperature. Handles 15 kg to 40 kg of rice.

Question 26

Describe Toko-koji

Answer 26

Steamed rice is placed on a special table, the toko. This method allows for a large volume of rice but does not allow for precise manipulation. Primarily used for futsushu.

Question 27

Middle Work is what step and takes place at what temperature?

Answer 27

Step 5 of 7; 35C

Question 28

Spread Seed is what step?

Answer 28

2 of 7

Question 29

Final Work is what step and what temperature?

Answer 29

6 of 7; It doesn't begin until reaching 38C and it is kept under 43C.

Question 30

What is the 3rd step of Koji making?

Answer 30

Re-breaking up. The temperature increases to 33C. Rice is mixed well to even the temperature and cool it to 31C.

Question 31

How long does koji-kin normally take to form? 1. Six hours 2. One day 3. Two to three days 4. One week

Answer 31

3. Two to three days

Question 32

What are the ideal conditions for koji mould growth?

Answer 32

High humidity and temperatures between 33C and 38C (92F-100F).

Question 33

What are the four stages of koji making?

Answer 33

1. Cooling the steamed rice to the right temperature 2. Innoculating the rice with koji spores 3. Initial mould growth 4. Controlling and stopping the mould growth.

Question 34

How is mould growth stopped?

Answer 34

The rice is moved to the coolest and driest part of the koji room.

Question 35

What is the look / feel / taste of koji rice?

Answer 35

Look: Koji rice looks like polished rice Feel: Koji rice has a crumby texture Taste: Koji rice has a slightly sweet chestnut flavour

Question 36

What are limit dextrans?

Answer 36

Limit dextrans are portions of the starch that the koji enzymes could not break into glucose. They are important because they provide sake's characteristic rich mouthfeel.