Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

WSET 3 -saké > Chapter 8: rice preparation > Flashcards

Chapter 8: rice preparation Flashcards

1
Q

What is an disadvantage of rice?

A

The energy is stored in the solid starch, rather than fermentable sugars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an advantage of rice?

A

It can be stored for months without rotting as long as its dried to a moisture of 15%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 4 steps to make the solid starch available?

A

-Polishing
-Washing
-Soaking
-Steaming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 things a brewer is looking for to achieve during rice preparation?

A
  1. Reduce the level of lipids,proteins,minerals and vitamins (too high levels = faster fermentation and add flavours)
  2. Adjust the amount and distribution of moisture within te rice grain (helps koji mould to penetrate to the centre and helps the grain to break up more easily)
  3. Gelatinise the starch so that the koji mould enzymes can break the starch into sugar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the husk of rice?

A

-The hard outer that protects the grain
-Removed immediatel after harvest
-remaining: brown rice, polishing ratio of 100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is in the bran?

A

-Starch
-Also: proteins,lipids,vitamins and minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Is the bran often used with sake production?

A

-No, it is made up from different layers and turns the rice from brown to white during polishing
- rarely used for sake production (although permited with junmai) because its difficult to propogate koji mould on bran and an excess amount of nutrients would make fermentation control difficult = unbalanced, rough flavours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the germ?

A

The part of the grain that will grow into a new rice plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is the germ removed during polishing?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is endosperm? What does it contain?

A

-The white layers below the bran
-Very high in starch, outer layers also contain protein, lipids etc = much lower in sake specific rice than table rice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is shinpaku?

A

-Only in sake specific rice
-Clearly defined section at centre of endosperm
-made with round-shaped granules of starch that are held in place by surrounding endosperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the advantages of a Shinpaku?

A

-Good at absorbing water: soft part, absorbs water quicker
-Very suitable for koji making: koji propagates more easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the differences between yamada Nishiki and Omachi regarding the Shinpaku?

A

-yamada= disc-shaped shinpaku (ideal for polishing to a low polishing ratio)
-Omachi = big ball-shaped shinpaku but cracks more easily during polishing and rice washing
-bigger shaped shinpaku not always good results in sake making

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is sugar stored in most plants?

A

-Sugar is vital for life, living things want reserves of sugar to support them in an event of shortage
-storing sugar not space efficient, can be dissolved when it comes into contact with water easy way is storage in starch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When a starch molecule is extending by adding another sugar molecule, 2 things can happen. Explain

A

-Simplest: sugar molecule is added at the end to make the starch chain lonfer withou changing its shape
-Or: can be added to create a side branch to the starch molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is amylose?

A

Structure with an almost straight chain of glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is amylopectin?

A

The latter structure with branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When is the rice sticky/glutinous?

A

When the starch molecules in a rice grain are made up of 80-100% amylopectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When is the rice non-sticky/non-glutinous?

A

If a rice grain contains less than 80% amylopectin and at least 20% amylose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where does increased amylose content leads to?

A

Reduces enzymatic digestibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do rice grains store starch?

A

Starch molecules are rolled up into granules stored within the cell walls
-space efficient way to store sugar
-Cell walls act as a barrier to protect the tightly bundled starh from being dissolved in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is gelatinisation?

A

-Process where the tightly wound starch granules are unravelled by breaking into intermolecular bonds beween starch molecules
-Opens up the starch chains so they become water soluble nd can be broken up by enzymes dissolved in that water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does gelatinisation require to take place?

A

Heat, thus takes place during steaming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the temperatures for rice gelatinisation? how is it compared to other cereal grains?

A

-70-80 degrees, relatively high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Name 1 reason why koji enzymes are needed for enzymatic hydrolysis
Because the temperature is too high for the rice germ's own enzymes
26
What happens during enzymatic hydrolysis?
-It breaks the starch grains into glucose molecules -needs: water and amylase enzymes -alpha amylase breaks the non-branching amylose starch chains into smaller fragments = dextrins
27
What happens after starch chains are broken up into smaller fragments (dextrins)?
-Glucoamylase can then remove the glucose molecules at the end of the chains -CANNOT separate the glucose where there is an amylopectin branch in the starch molecule
28
what is the remaining branched fragment called?
Limit dextrin
29
Do dextrin fragments remain in the sake?
Yes, giving a sticky mouth coating texture to the liquid
30
When does enzymatic hydrolysis take place?
during fermentation, a.k.a. enzymatic digestion
31
If a robust and flavoursome style of sake is sought, what are the choices the brewer will likely make?
-fast fermentation at higher temperature -higher levels of koji -rice does not have to be sake specific nor highly polished
32
If a producer seeks to make a delicate, light-textured daiginjo, what choices will he make?
- polishing the rice to low ratio -careful washing, good soaking and steaming to produce the right amount of koji because if enzymatic digestion is too quick, too fast fermentation cold, slow fermentation to produce fruity aromas
33
Which nutrients are important for the growth of koji mould?
-bran and outer layers of the endosperm contains protein,lipids,vitamins and minerals which are important for the growth of koji mould and yeast.
34
What happens with koji if there is a lot of protein, lipids etc available?
- higher koji mould propagation -fast fermentation -large amount of sugar (due to koji propagation) + warm fermentations = difficult to have elegant flavuirs that need a long and cool fermentation in order to develop.
35
What is the taste called as a result from rice proteins? what if there are too many rice proteins?
-Umami -too many = rough and heavy texture
36
Why does sake need to be polished slowly and gently?
Otherwise the rice grains dry out and become cracked due to the heat and fraction generated by the polishing
37
What is used for polishing now and traditionally?
-Now: high-speed rotating roller -traditionally: pedal-driven mills or by watermills, 80-90% max polishing ratio
38
How does a vertical rice polishing machine works?
-Brown, unpolished rice is dropped into the polishing column -rock grinding roller rubs away the outer layers of the grains of the rice
39
What is the fine rice powder called which remains from the vertical rice polishing machine? Where is it used for?
-Nuka -not use for sake, sold for rice oil, animal feed, rice cakes and glue
40
What are the 2 stages of polishing?
-coarse grinding roller rapidly removes bran and endospwem -switches to finer-textured grinding roller with a slow speed for a later stage where rice gets smaller and more fragile
41
Where is the nuka separated from the rice?
Below the polishing olumn at the bottom of the machine
42
Why are the rice grains sent back to the top of the tank?
To be polished until the grains are polished to the required ratio
43
How long does it take to polish 600 kg of brown rice for honjozo level?
10 hours to reach 70%
44
How long does it take to polish 600 kg of brown rice for daiginjo level?
45 hours to reach 50%
45
What happens after the polishing ratio (seimai-buai) is achieved? why?
-Rice is rested to be cooled down and reabsorb some of the moisture lost during polishing -Reduces the risk of cracks appearing on the rice caused by temperature change -cooling & moisture can take 3-4 weeks
46
What is the purpose of washing?
-Removing remaining nuka without allowing the rice to reabsorb too much water -Water that is absorbed, absorbed evenly by the grains
47
What are the 2 options for washing?
-Hand washing in small batches (traditional, premium sake) -Rice washing machines -> now also as good as hand washing
48
How does a rice washing machine works?
-Blow fine air bubbles through the water replicating hand stirring -Brings all rice in contact with the water and gets the dusts off the rice
49
How are futsu-shu sake washed?
-large-scale washing tanks
50
What is the purpose of soaking?
-To increase its water content to the optimal level before steaming -Moisture level raised to 30-35% depending on the rice variety and polishing ratio and if rice is used for koji or not
51
What happens is the sake is soaked too long? what are the reasons why it is not good for quality?
- The outside of the grains absorb too much water -2 reasons: (1)if rice is destined to become koji, mould will grow too quickly without producing sufficient koji enzymes (2) if over moist rice is used for fermentation, enzymatic digestion happens too quickly resulting in yeast having access to high sugar levels -> hard to control for brewer, not wanted for (dai)ginjo
52
The more the rice is polished the less time is takes to absorb the water (true or false?)
True
53
Does it get more difficult to enzymatically digest the rice in hot summers? how can this be compensated?
Yes, can be compensated by longer soaking
54
Rice firmness/absorbency is for all rice varieties the same (true/false)
False
55
Warmer water is absorbed by the rice more slowly (true/false)
False, cold water is absorbed more slowly (between 5-8 degrees) but water temperatures can change due to ambient temperature
56
The brewer must consider the target moisture level of the rice (true/false)
True
57
What does the brewer do to achieve the target water absorption?
Starts with a few trial batches, experimenting with adjustments by checking the rice and measuring the water absorbed each time
58
Why does rice with a lower polishing ratio (<50%) absorb water more quickly?
Is drier and more porous and therefore absorbs water more quickly
59
What happens if rice with a low polishing ratio is left to soak?
It will continue to absorb water, way more than the ideal 30%, thus it should be controlled especially for ginjo styles
60
Does rice with a high polishing ratio (70%+) absorb water slowly or quickly? Why?
-Slowly because starts off with more moisture -The rate of water absorption slows with time -When it reaches 30%, water is hardly absorbed -> does not need to be monitored, can be left overnight to soak
61
What are 3 ways to control and achieve the right moisture level?
1. Soaking the rice in very small batches 2. Using cold water to slow down absorption 2. Timing the soaking using stopwatch
62
What happens after soaking?
-Rice must be drained -Left to rest several hours before steaming (less than 24 hours after soaking is finished)
63
Is soaked rice more fragile than unsoaked rice? why (not)?
-Yes because of the increased moisture level in the grains
64
What are the 3 purposes of steaming?
1.Sterilises the rice 2. Gelatinises the starch molecules 3. Further increase of moisture level (30% after soaking, 40% after steaming)
65
Explain how the traditional steamer is used and what needs to be considered
- Rice has to be well drained -Rice placed in steamer at night or on the morning of steaming -1 batch = 700 kg and steaming takes about 40-60 minutes -rice loaded into the steamers in layers separated with cloths (easier to load/unload steamer and separate the batches)
66
What is the aim of steaming regarding the grains?
-to be evenly cooked -firm on the outside and soft on the inside
67
Does rice used for koji production require higher or lower moisture levels? why?
-Higher levels to minimise cracking of the koji rice during steaming
68
Which layer in the steaming machine is used for koji production?
Top layer because it is easier to control the moisture level and minimising cracking compared to other layers
69
Why is the rice steamed in cloths?
To prevent the water condensation from surfaces dripping back onto the rice and making it wet
70
The rice in the other steaming layers are used for...
The fermentation starter or the main fermentation
71
In which layer are the moisture levels the highest? what problems can this cause?
-At the bottom of the steamer -Moisture levels can be too high, problem if the rice has low polishing ratio and used for ginjo style
72
What can brewers do to prevent too high moisture levels during steaming?
-Use bags of fake rice for the bottom of the steamer in order to raise the rice away from the steam and prevent the rice on the bottom layer from becoming too moist
73
What is a different technique regarding steaming some brewers use? How does it work?
-Special pressure heater to blow dry hot steam just before the steaming process is finished -Increased pressure raises the steam temperature and reduces the quantity of water droplets carried in the steam - Leaving more heat and less water on the outside of the rice -> firm on outside, soft on inside
74
Which steamers are used for large scale production? How does it work?
- Continuous steamer: conveyor (rice on one side and exit for steamed rice) -1st part: high pressure steam -2nd part: rice is cooled -30-40 minutes, many tonnes of rice per day
75
How do brewers decide if the rice is perfectly steamed?
-They shape rice into a round cake using their hands -Toughness is checked (as hard ad a tennis ball when squeezed) -Some check by chewing it with their front teeth

WSET 3 -saké (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions