Ch. 2: Sake Production

Question 1

Ingredients of Sake?

Answer 1

1) Steamed White Rice
2) Water
3) Koji
4) Yeast

Question 2

When is the rice planted and then harvested?

Answer 2

Planted in Spring, grown over the Summer and harvested in Autumn.

Question 3

How long can rice be stored?

Answer 3

Rice can be stored for a few months before is is ready to use.

Question 4

What are the subspecies groups of rice?

Answer 4

Indica - Long Grained
Japonica - Short Grained
*Glutinous - Sticky
*Non-Glutinous - Non-Sticky

Question 5

What are sake-specific rice varietals?

Answer 5

Varieties of rice developed for sake brewing. They are typically harder to farm and give lower yields.
Favored for 3 reasons (All of which make it easier to polish the rice grains)
1) Less protein then table rice
2) Most of the starch granules lie in the well-defined almost pure starch core
3) Larger grained, so less likely to crack

Question 6

Basic process needed for sake production?

Answer 6

Polished rice is a solid with a starchy core that needs water and koji produced enzymes to convert the solid starch into a sugary fermentable liquid. Yeast is then needed to ferment the sugars into alcohol.

Question 7

What is the 1st step of production?

Answer 7

Polishing

Question 8

How is polishing done and what is it’s purpose?

Answer 8

Polishing is done mechanically in large rice-polishing machines.
Polishing removes the proteins, lipids, vitamins and minerals that are concentrated in the outer part of the ride grain, leaving just the starchy core.

Question 9

What is the polishing ratio?

Answer 9

Polishing ratio is the amount of rice that remains, which is what is used to determine the final style and category of the sake.

Question 10

What is the 2nd Step of production?

Answer 10

Washing

Question 11

How is washing done and what is it’s purpose?

Answer 11

Washing is done either in small containers, large vats or continuous rice polishing machines.
This process removes any remaining fine rice particles that would otherwise make the sake less pure, rougher in texture and more acidic.

Question 12

Profile of sake made with highly polished rice

Answer 12

purer, fruitier flavor, and i lighter in body with lower acidity and umami.

Question 13

Profile of sake made with coarsely polished rice

Answer 13

more savory notes with less fruit and more body and, more acidity and more umami.

Question 14

What is the 3rd Step of production?

Answer 14

Soaking

Question 15

How is Soaking done and what is it’s purpose?

Answer 15

For the purest and most delicate Sakes, soaking is done in small batches and timed precisely. For other styles, soaking is done over a few hours in large tanks.
Soaking alters the amount and distribution of water within the rice grain, ensuring the inner starchy core is soft and moist.

Question 16

What is the 4th step of production?

Answer 16

Steaming

Question 17

How is Steaming done and what is it’s purpose?

Answer 17

Traditionally, steaming is done in 1 ton batches for 1 hour. Larger brewers have continuous rice steamers.

1) Steaming ensures the outside stays firm (unlike boiling) to ensure the rice receives the koji properly and also breaks up correctly during fermentation.
2) The heat also changes the structure of the starch, allowing the Koji enzymes ti break it up into ferment-able sugars.
3) Steaming also disinfects the rice

Question 18

What is starch?

Answer 18

Starch is a large molecule made up of a lot of sugar molecules tightly linked together in a chain. This chain must be broken up into sugars before yeast can ferment them into alcohol

Question 19

What are enzymes?

Answer 19

Enzymes are a kind of protein that helps chemical reactions take place with out being used up in those chemical reactions, so only small amounts of enzymes are needed to convert large amounts of starch into sugar.

Question 20

What is Koji Mould and Koji?

Answer 20

Koji Mold: a specialized naturally occurring mold that creates starch-converting enzymes .
Koji: Moldy rice that is created by allowing Koji mold to grow on steamed rice.

Question 21

What is the 5th step of production?

Answer 21

Creating Koji

Question 22

How is Koji created?

Answer 22

Koji is created in a special series of rooms in a sake brewery where the temperature and humidity can be controlled. There are 4 steps:

1) Cooling the rice
2) Inoculation of the rice by sprinkling Koji mold spores on the thinly spread cooled rice
3) Initial mold growth, the rice and mold are mixed to ensure thorough mold growth over all rice grains.
4) Controlling and stopping the mold growth. The temperature is precisely controlled to ensure just the right amount of mold is grown and eventually the temperature is dropped to stop the production.
* **Typically takes about 2 days.

Question 23

What conditions does Koji need to grow?

Answer 23

High humidity and warm temperatures of between 33C and 38C (92-100*F)

Question 24

Profile of sake produced with Koji that has High Koji Mold levels

Answer 24

Large amounts of enzymes are produced, so starch is converted into ferment-able sugars more rapidly, leads to faster fermentation and the sake tends to have more flavor intensity, with more acidity and umami

Question 25

Profile of sake produced with Koji that has low Koji Mold levels

Answer 25

smaller amounts of enzymes are produced, so starch is converted into ferment-able sugars more slowly, leads to slower fermentation and the sake tends to be lighter in flavor with less acidity and umami.
***This must be precisely produced and makes a purer, more delicate style of ginjo.

Question 26

What kind of water is used and how does it influence the style of sake?

Answer 26

As long as it is clean and the iron concentration is low, almost any water can be used. However the mineral concentration affects fermentation and therefore the style of sake.

Question 27

What kind of Yeast is used?

Answer 27

Special yeast strains are needed to cope with the unique conditions of sake fermentation.

1) They must keep working in a high alcohol environment that reach over 20% ABV
2) Tolerate cold environment, which can be as low as 6*C.
3) Tolerate very low levels of sugar

Question 28

How can Yeast influence the style of sake?

Answer 28

Yeast can contribute high levels of aromas, some being sought after for their specific aromatic characteristics.

Question 29

What is the 6th Step of Production?

Answer 29

Fermentation

Question 30

How is Fermentation done?

Answer 30

There are 2 steps of fermentation.
The fermentation starter and the Main fermentation.
These are completed in large open air vats that are temperature controlled.

Question 31

What is the fermentation Starter?

Answer 31

A small portion of the yeast, water, Koji and steamed rice is mixed together in a smaller batch ti give better control and resist any contamination while the yeast population builds.
*Very often, Lactic acid is added to the starter to ensure contamination does not occur. This acid kills off any other spoilage microbes, while the special yeast is resistant to it.

Question 32

How does the Main Fermentation happen?

Answer 32

The fermentation is built in stages to protect against contamination.
Day 1: 1/6 of the ingredients, plus the fermentation starter is mixed together.
Day 2: Nothing is added, yeast from the starter is allowed to multiply.
Day 3: About 2/6 (1/3 or twice as much as day 1) of the total ingredients are added and yeast multiplies.
Day 4: Remaining 3/6 of the total ingredients is added and yeast multiplies and fills the tank.
***After this, it takes approximately 3 to 5 weeks to complete fermentation. The colder the temp, the longer the fermentation.

Question 33

What 2 processes are happening in unison in the Main Fermentation tank?

Answer 33

Koji Enzymes are breaking down the starches into sugars and the the Yeast is converting the sugars into alcohol with the by products of heat and CO2

Question 34

What are the fermentation temperatures>

Answer 34

Relatively cool, from 6C to 18C (43-64*F)

• Warmer Temps create fuller bodied sakes, with more cereal and spicy/earthy flavors.
• *Cooler temps create lighter bodied, floral.fruity sakes.
• **Ginjo stylkes use extremely cold and slow fermentations which strains the yeast and creates notes of green apples and fresh bananas.

Question 35

What is the optional step after fermentation, but before filtration, and why?

Answer 35

Addition of Jozo Alcohol. Sake flavors dissolve more in alcohol than in water so the addition of Jozo ensures more intense flavors remain in the sake and do not get filtered out with the solids.
*Water is added later to reduce the ABV back to the 15-17% ABV range

Question 36

What is the 7th Step of production?

Answer 36

Filtration

Question 37

Is Filtered sake stable? What can happen?

Answer 37

No, Microbial contamination and/or The Koji Enzymes (Not removed during filtration) remain active and can continue to convert starch to sugar creating unpleasant flavors.

Question 38

What is pasteurization?

Answer 38

The sake is heated over a long period of time killing unwanted microbes and destroying the koji. Typically done twice, before tank storage and either right before or after bottling. (the closure ensure no further contamination can happen)

Question 39

Are all sakes pasteurized?

Answer 39

No, called Nama, or Nama Zakes