Yeast

Question 1

Yeast playes a critical role in determining what two things?

Answer 1

Quality and style

Question 2

When did the Brewing Society of Japan begin distributing yeast?

Answer 2

1906

Question 3

How is yeast selected?

Answer 3

Yeasts were selected and isolated from the main fermentation mash of breweries that had produced good sake.

Question 4

By law, all sake breweries must purchase their yeast from the Brewing Society of Japan. T or F

Answer 4

False Many breweries have proprietary strains.

Question 5

Kyōkai kōbo

Answer 5

Yeast from the Brewing Society of Japan, also called Brewing Society Yeast.

Question 6

Foamless Yeast

Answer 6

• add -01 suffix
  
  • ex: #901 is a foamless #9
• no foam rises in the tank, making it easier to work with and clean up
  
  • dried foam is concentrated with microbes– posing a serious risk of spoilage
• foamless yeast is extremely popular

Question 7

What is an advantage of foamless yeast?

Answer 7

Dried foam is concentrated with microbes– posing a serious risk of spoilage

Question 8

What are the reliable fermenters?

Answer 8

6, #7, #11

Question 9

Brewers have been utilizing microbial technology to produce yeasts designed to increase the amount of _______________ delivering a ______________ aroma.

Answer 9

Brewers have been utilizing microbial technology to produce yeasts designed to increase the amount of esters delivering a fruity aroma.

Question 10

Why are special yeast strains needed?

Answer 10

They must be able to keep working in a higher alcohol environment (20%abv or higher), they must be abe to work at low temperatures, and they may need to work with low levels of sugar.

Question 11

Yeast need what?

Answer 11

From rice: Sugar and other nutrients

From rice + koji: vitamins and nitrogen

From rice + water: magnesium, phosphorous, potassium

Question 12

Most sakes are made using ambient yeast.

T or F

Answer 12

False

Question 13

What are three ways to blend yeasts?

Answer 13

1. add a mix of yeast strains to the starter.
2. create multiple fermentation starters, each with a unique strain, then combine the starters for fermentation.
3. create multiple batches of sake, each with a unique yeast, and blend the sakes at some stage after fermentation.

Question 14

Brewers are still experimenting to determine the best methods for combining yeasts.

T or F

Answer 14

True

Question 15

More than anything else, yeast determines what?

Answer 15

aromatics

Question 16

Nihon jouzou kyoukai

Answer 16

Brewing Society of Japan

Question 17

01 on a yeast indicates what?

Answer 17

Low foaming

Question 18

In general, the higher the number the lower the aromatics.

T or F

Answer 18

False