C11 - The Fermentation Starter (Shubo/Moto) - completed

Question 1

what is the common aim of the producers using fermentation starter in different alcoholic beverage?

Answer 1

to produce a healthy population of their selected yeast

Question 2

what is the function of the shubo/moto?

Answer 2

• create an acidic environment using lactic acid
• develop a sufficient, concentrated population of fermentation yeast
• in order to carry out the main fermentation successfully

Question 3

percentage of the small shubo tank compare with the size of the main fermentation tank

Answer 3

6 - 10%

Question 4

what’s special about the koji used in making shubo vs. in the main fermentation?

Answer 4

• relatively high in proportion

- typically 30 - 33% of the rice used is koji

Question 5

typically what’s the percentage of koji rice is used across the whole fermentation?

Answer 5

20 - 23%

Question 6

how long it takes to make a shubo?

Answer 6

14 - 28 days (depends on method)

Question 7

what techniques the brewers use to manage the shubo making process?

Answer 7

• by managing the temperature and the acidity of the shubo

Question 8

which tool is used for adjusting the temperature during shubo production?

Answer 8

daki - a bucket-like container, made from aluminium or stainless steel

Question 9

why temperature control is important when making shubo?

Answer 9

• need to ensure the yeast multiply at the same pace as the koji mould enzymes convert starch to sugar

Question 10

other than daki, what other devices can be used to adjust the temperature?

Answer 10

pipes or jackets of hot or cold water

Question 11

what are the ingredient of shubo?

Answer 11

rice, water, koji, (lactic acid)

Question 12

why microbial contamination is a major risk in making sake?

Answer 12

• when steamed rice, water and koji mixed together, it’s low acidic, cannot protect the yeast
• shubo is a very attractive environment to microorganisms
• koji mould enzymes is slow in converting starch to sugar, means less food to support rapid yeast population
• bacteria multiply much more faster than yeast

Question 13

in order to protect the yeast to populate in shubo, what is needed?

Answer 13

• high level of lactic acid

Question 14

what are the 3 methods of making shubo?

Answer 14

• sokujo-moto
• kimoto
• yamahai

Question 15

which method is the most common in making shubo?

Answer 15

• sokujo-moto

Question 16

what is the disadvantage of the kimoto/yamahai method?

Answer 16

• it’s vulnerable to spoilage

- take longer time

Question 17

are sokujo-moto, kimoto, yamahai legally defined terms?

Answer 17

No

Question 18

which method is a reliable way to create shubo during 1600s to mid 1800s?

Answer 18

kimoto

Question 19

when did the brewers start to discover how the kimoto method works scientifically?

Answer 19

late 1800s

Question 20

what was the findings in late 1800s when discovering why kimoto works?

Answer 20

• it’s the lactic acid which protect the yeast

- this ultimately led to the development of sokujo-moto.

Question 21

when did sokujo-moto development become perfect?

Answer 21

the early 1900s

Question 22

what is the major difference in making sokujo-moto with kimoto/yamahai?

Answer 22

• it adds lactic acid directly to the shubo

Question 23

what else sokujo-moto changed the way of making shubo for centuries?

Answer 23

• it raised the temperature to 20 - 25C

- ideal for both koji enzyme extraction and the yeast multiplication

Question 24

what was the temperature range in making shubo in the old days?

Answer 24

6 - 7C

Question 25

what are the difference in terms of results of sokujo-moto vs kimoto/yamahai?

Answer 25

- it's faster, take 14 days instead of 28 days. - it has more precise control in the level of lactic acid, usually lower than kimoto/yamahai - the shorter time and no need to rely on lactic acid bacteria avoids variations that may led to failure - less umami in flavour

Question 26

what is the advancement of sokujo-moto recently?

Answer 26

- the "fast sokujo" or 'medium temperature sokujo' - start from a even higher temperature - complete in 10 days

Question 27

where and when did the prototype of kimoto develop?

Answer 27

- Nada | - late 1600s

Question 28

how kimoto is made?

Answer 28

- starting with a small batch | - keeps pounding the rice and koji into a smooth paste with poles or paddles

Question 29

why pounding in kimoto is neccessary?

Answer 29

- this increase the contact of the rice starch and koji enzymes - speed up the conversion process - thus speed up the yeast population - thus yeast becomes the dominant bacteria faster

Question 30

what temperature range kimoto starts from?

Answer 30

6 - 7C

Question 31

in the initial stage of making kimoto, which process starts first, before any microorganism begin to grow?

Answer 31

the starch to sugar conversion

Question 32

what is the only bacteria take place in the initial stage of making kimoto?

Answer 32

- those convert nitrates to nitrites

Question 33

which one is the cold-tolerant bacteria in the initial stage of making kimoto?

Answer 33

lactic acid bateria

Question 34

describe the environment of kimoto which inhibit unwanted microbes to grow

Answer 34

- high concentration of sugar - low pH (high acidity) due to lactic acid - low temperature (6-7C) - presence of nitrites

Question 35

why kimoto method is more prone to spoilage?

Answer 35

because before the acidity level is high enough, unwanted bacteria still have chance to spoil the shubo.

Question 36

today, what is the timing of adding yeast to kimoto?

Answer 36

14 days from the start of making kimoto

Question 37

how long the added yeast takes to multiply until the kimoto is ready?

Answer 37

another 14 days. (total 28 days)

Question 38

what is the major difference between kimoto and yamahai in terms of process?

Answer 38

- yamahai mix koji and water together, and then steamed rice, to start the starch to sugar conversion, - no need of the laborious pounding process as in kimoto

Question 39

which year was yamahai discovered by scientist?

Answer 39

1909

Question 40

why some brewers still use kimoto/yamahai despite the extra time and risk?

Answer 40

- the active microbes can produce interesting flavours - rich flavours - higher acidity - complex nutty and caramel flavours from deliberate oxidation

Question 41

what are the other options of creating shubo?

Answer 41

- ko-on toka moto - bodai moto - use mechanical mixers in the mixing stages of kimoto - no shubo - use black or white koji mould

Question 42

what's special about ko-on toka moto?

Answer 42

- it use very high temperature in the initial stage to sterilise the mixture and accelerate the starch to sugar conversion - it's suitable for very pure, clean style of permium sake

Question 43

what's special about bodai moto?

Answer 43

- it use sour water to play the role of lactic acid in sokujo-moto - the sour water comes from mixing bacteria decay rice into water

Question 44

what's special about black and white koji mould?

Answer 44

- they create higher and different acid (citric acid) - the acidity level is enough to start a fermentation with small yeast population - these koji moulds were normally used for making shochu