Ch. 2 Relationship between Fermentation, Microorganisms and Enzymes Flashcards
What are the 3 groups microorganisms that alcoholic beverages and fermented foods can be divided into?
Bacteria, yeast, fungus
Fungus can be seen with naked eyes
Yeast & bacteria require microscope
What bacterias are found through fermented foods?
Acetic bacteria
Lactic acid bacteria (can survive without oxygen)
Koji mold cannot survive without ______
oxygen
What is fermentation versus rotting
Fermentation is convenient for humans
Rotting is not helpful to humans
What is the microorganism induction phase
When they awaken and begin to reproduce
What are the four stages of reproduction of microorganisms (yeast chart)
- Induction phase
- Logarithmic Growth Phase
- Stationary Phase
- Death phase
What is the logarithmic growth phase
When the population doubles and doubles
yeast produces alcohol and carbon dioxide
Temperature rises
What is the stationary phase in yeast growth
When the alcohol concentration gets higher
growth trajectory flattens
What is the death phase
Rise in alcohol concentration
Lack of nutrients
What temperature is many microorganisms most reproductive?
30C
What temperature are sake yeasts active?
At lower temperatures than other yeast. 8-17C
What is pH and what rating is neutral?
Indicator of acidity or alkilinity
Ph7 is neutral
Lower than 7 indicates acidity
Higher indicates alkilinity
Sake Ph 4.2
What are the limits of abv% for wine yeast to survive?
13% - 15%
What are the limits of abv% for sake yeast to survive?
18% - 20%
Starch chains (chains of glucose clusters) are broken up into short chains called ___________
Dextrin clusters. Dextrin is water-soluble
What is hiochi kin and up to what percentage of alcohol can it survive?
It is a type of lactic bacteria which causes problems in chozu-shu and can grow even in 21% abv
Definition of enzyme
A generic term for proteins that function as a catalyst
What is the definition of a catalyst
A substance that expedites the rate of a chemical reaction without itself undergoing any chemical change
What breaks down starch?
Amylase
What breaks down protein?
Protease
What breaks down fat?
Lipase
At what temperature do enzymes generally lose their functionality and why?
60C because the structure of the protein is destroyed due to thermal denaturalization
What are the four major enzymes found in yellow koji for sake making?
- Alpha-amylase
- Glucoamylase
- Acid Protease
- Acid Carboxypeptidase
What does alpha-amylase do?
Breaks down starch into dextrin
Starch chains are not water soluble while dextrin is
What does glucoamylase do?
Breaks down dextrin into glucose
Not all starch of steamed rice is broken all the way down to glucose. Some short branches remain
A mixture of dextrin and glucose resembles a ___________
glutinous starch syrup
What does acid protease do?
Breaks down protein into peptide
Long chains are proteins
Short chains are peptides
Both protein and peptides are ________
Amino acids
What does acid carboxypeptidase do?
Breaks down peptides into amino acids
What is tanshikihakko 単氏
Simple fermentation like wine
What is saccharification?
The process of breaking down starch to glucose
What is tanko-fukushiki-hakko 単行腹式 ?
Multiple sequential fermentation
What is seikiku
Koji making
What is the role of koji
- to supply the enzymes requires to break down starch and proteins in steamed rice
- to provide vitamins and other nutrients to promote the growth of yeast
How long does it take to become koji?
Normally 2 days
What are the two rooms in the koji-muro?
- Toko-kikan where rice is set on the toko “bed” used for koji making on the 1st day
- Tana-kikan from second day onward used for storing rice on shelves
What is the normal temperature in the koji-muro and how is the air
Usually 32C and dry due to cold winter air
What is the name of companies that produce tane-koji?
Moyashi-ya
What are the two japanese names for koji mold spores granular substance?
tane-koji
moyashi
Several strains of koji are __________ to make a tane koji
blended together
What is the first step of Seikiku Day 1?
What temperature does the steamed rice reach?
Hikikomi - when the steamed rice is brought into the koji-muro and laid onto the toko.
The steamed rice is cooled from slightly above 36C to the desired temperature while ensuring a consistent teperature across the bed
What is the second step of Seikiku Day 1?
Tanekiri - spreading tane-koji onto the rice
Use a fine wire mesh or cloth to prevent clumping
Sprinkled from a height of >50cm
Allow 1 minute for the spores to settle onto the steamed rice
Then the layer of rice is flipped over and the tanekiri process is repeated
Can be done mechanically or manually
What is the third step of Seikiku Day 1?
Hikikomi - Tanekiri - _______
Toko-momi: when steamed rice is well mixed to ensure spores attached evenly to each grain of rice. Then rice is wrapped in cloth to prevent drying
What is the target water absorption rate after tane-kiri for ginjo versus futsu
32% for ginjoshu, 33% for futsu
While more moisture generally helps the growth of koji-kin, a somewhat lower absorption rate is preferable for developing the vital enzyme, ____________
Glucoamylase
Koji-kin spores only germinate at above ______ relative humidity
97%
What is the first step Day 2 koji making?
Kiri-kaeshi. Can also be done 8-10 hours after toko-momi
Grains of koji are stuck together, it is then broken apart either by machine or sieve
What is the second step of day 2 koji making
Mori: controlling the temperature generated by the koji mold by dividing it into smaller portions
Also helps the koji-kin from dying due to lack of oxygen
Hako process:
Koji is laid in thick layers of 6-8 cm
Cotton flannel breathable cloth placed over box to avoid drying. Contact of cloth to koji layers must be avoided
What are the 4 different processes during the mori step of koji making
1: Futa (lid)
1.5kg of koji. Slit shaped openings for ventilation. Stacked when in use
Cons: requires tsumi-kae (re-stacking) which needs to be done at night
2: Hako (box)
3: Toko (bed)
4: Hanjidou-seikikuki (semi-automatic machine) or zenjidou-seikikuki (fully automatic machine)
It is a toko with a fan
What is the ideal maximum temperature of koji to achieve the ideal balance of enzymes as well as productivity?
40-43C
At what temperature does koji stop growing?
45C
The ideal temperature path for koji that most breweries take results in koji with more ___________ and less _______________
- Glucoamylase
- Acid carboxypeptidase
At what temperature is acid carboxypeptidase abundantly produced in koji
35C so it is necessary to pass through this temperature range quickly
The longer the duration of the maximum temperature, the more ___________ is produced
Glucoamylase
What is the 3rd step of the 2nd day of koji making
Kiri-kaeshi - Mori - __________
Naka-shigoto: remixing
Performed 6-10 hours after mori
Koji temperature would have risen to 34C-36C
Amount of fungus spread on surface is called haze-mawari
What is the final 4th step of the 2nd day of koji making
Kiri-kaeshi - mori - nakashigoto - _______
Shimai-shigoto meaning final job of the day
Koji would be at 38C-39C
Hazemawari at 70%
Kurika smell and sweet taste
Then the work is to adjust the final temperature to 36C-38C using same method as naka-shigoto.
Koji layer to a thickness of 4-5cm
After several hours, koji reached peak temp of 40C-43C and stabilize
What is kurika
smell of chestnut flowers
What is the 1st step of koji making on the 3rd day and how is the koji checked
De-koji
The process of taking koji out of the koji-muro
Koji spread out, clumps are broken down to release moisture and heat
Checked for sweetness (time elapsed after kurika) and grain is cracked open to confirm haze-komi (degree to which koji-kin was grown into the center of the grain)
Today a tracing light board and 10x magnifying lens used to evaluate amount of threads and density of conidial heads
What is the name of determining the timing of de-koji
de-koji hantei
De-koji for ordinary sake comes ________. Less ________ are observed
sooner
mold hyphae
If _______ are formed, it is past the ideal time for de-koji
spores
What is the last step of koji making on the 3rd day
De-koji kanso: the process in which koji-kin is dried
What is the process called when leaving koji to dry for a day after de-koji kanso
Koji-no-karashi
It has a bactericidal effect and growth of koji-kin can be stopped at best timing before spores are formed. Koji-kin is then not aged
Quality of resulting sake is better when leaving the koji to dry. Acidity lower by 0.2, fresher aroma with lighter, less rougher taste
What is the process caled when adding the koji to the moromi the day of de-koji?
de-zukai
