Unit 1 - Malt - Steeping

Question 1

What is the purpose of steeping in the malting process?

Answer 1

To increase the kernel moisture level from storage to optimum for germination

Steeping increases grain moisture from typically 10-12% to around 45%

Question 2

At what moisture level does germination start?

Answer 2

Above 30%

Moisture levels of 32-35% are effective for germination

Question 3

What negative effect can moisture levels exceeding 46% have?

Answer 3

Can negatively affect germination

Question 4

What are the byproducts of respiration during germination?

Answer 4

• CO2
• Water
• Heat

Question 5

What is the ideal moisture level for germination?

Answer 5

Between 43-46% in the whole kernel

Question 6

How does water enter the grain?

Answer 6

Through the micropyle

Question 7

What effect does temperature have on water uptake in grains?

Answer 7

Water uptake is faster at higher temperatures

Question 8

Fill in the blank: Smaller grains absorb water ______ than larger grains.

Answer 8

faster

Question 9

How do steely grains differ from mealy grains in water absorption?

Answer 9

Steely grains draw water up more slowly than mealy grains

Question 10

What is the germinative capacity (GC) test used for?

Answer 10

To check whether barley is acceptable for intake

Question 11

What does a pink stain indicate in the GC test?

Answer 11

Living embryos

Question 12

What is measured in the germinative energy (GE) test?

Answer 12

Rootlet growth in grains

Question 13

What does dormancy in seeds prevent?

Answer 13

Germinating under false starts

Question 14

What is water sensitivity in grains?

Answer 14

A condition where grains do not germinate when there is excess water

Question 15

How is water sensitivity calculated?

Answer 15

Water sensitivity = number of germinated grains in 4 mL test - number of germinated grains in 8 mL test

Question 16

What hormone stimulates enzyme production during malting?

Answer 16

Gibberellic acid (GA)

Question 17

List key enzymes synthesized de novo in response to GA.

Answer 17

• α-Amylase
• Limit dextrinase
• Endoproteases

Question 18

What must barley be free from before malting?

Answer 18

• Stones
• Metal
• Foreign seed
• Other materials (dust, broken grains, husks, stalks)

Question 19

What is the purpose of a steeping vessel?

Answer 19

• Hydrate the grain
• Remove CO2
• Remove toxic metabolites
• Remove microorganisms
• Remove excess heat
• Provide oxygen
• Enable air rests

Question 20

True or False: Conical steeps are actually conical in shape.

Answer 20

False

Question 21

What is the major advantage of conical steep vessels?

Answer 21

Easier emptying due to gravity flow

Question 22

What is a Giracleur used for in steeping vessels?

Answer 22

To level the barley and prevent dry pockets

Question 23

In flat-bottom steeps, what type of floor is usually constructed?

Answer 23

Wedge wire

Question 24

What happens during air rests in steeping vessels?

Answer 24

Barley respires vigorously, producing CO2 that must be removed

Question 25

What is the role of aeration nozzles in flat-bottom steep vessels?

Answer 25

To ventilate and mix the barley

Question 26

What can happen if oxygen is not replaced during respiration in steeping?

Answer 26

Respiration slows and eventually stops

Question 27

What is the purpose of the loading spreader in the steeping process?

Answer 27

To draw up barley and deposit it on the surface

Question 28

What happens to barley during the air rests?

Answer 28

Barley respires more vigorously, heating up and producing CO2

Question 29

What must be removed and replaced with fresh air during air rests?

Answer 29

CO2

Question 30

What is the effect of a lack of oxygen on barley respiration?

Answer 30

Slows respiration and eventually stops it

Question 31

What happens in an atmosphere containing 80% CO2 for barley?

Answer 31

Chitting occurs but embryo development is severely impaired

Question 32

How is air introduced in a flat-bottom steep?

Answer 32

Air is blown in from underneath or above

Question 33

How is air introduced in a conical steep?

Answer 33

An external fan draws air through the grain bed from below

Question 34

What are the three purposes of adding fresh air during the air rest?

Answer 34

* Removal of CO2 * Removal of heat * Provision of oxygen

Question 35

What is the definition of steeping?

Answer 35

Not simply immersing grain in water, but submerging for set periods and draining at intervals

Question 36

What qualities should water used for steeping have?

Answer 36

* Clean and potable * Free of pathogens, dissolved organic material, and heavy metals * Low chlorine levels

Question 37

What factors influence the steeping programme for grain?

Answer 37

* Variety * Season * Time after harvest

Question 38

What is needed to establish an appropriate steeping programme?

Answer 38

* Varietal purity * Current moisture level * Germinative energy * Germinative capacity * Water sensitivity * Total nitrogen

Question 39

What is the temperature range for the first immersion in the steeping cycle?

Answer 39

12-15°C

Question 40

What is the typical temperature range during the first air rest?

Answer 40

12-14°C

Question 41

What should be done for water sensitive barley during the steeping process?

Answer 41

Shorter immersions followed by longer air rests

Question 42

What moisture level is suitable to initiate germination in barley?

Answer 42

30-33%

Question 43

What is the maximum grain temperature during an air rest to avoid damage?

Answer 43

23°C

Question 44

What is the typical temperature range for water and air during barley growth?

Answer 44

9-16°C

Question 45

What must not exceed 21-23°C to avoid damaging the grain?

Answer 45

Grain temperature

Question 46

Fill in the blank: Water sensitive grain should have a ______ initial immersion, followed by a longer air rest.

Answer 46

short