Malting Process

Question 1

What is Steeping?

Answer 1

The seed is soaked in water to encourage it to grow

Question 2

What’s the ideal moisture content for germination?

Answer 2

43-46%

Question 3

At what percentage does germination begin to start?

Answer 3

30 -35% - Germination activates the biochemical processes that synthesise key enzymes

Question 4

What plant growth hormone initiates the production of crucial enzymes?

Answer 4

Gibberellic acid (triggered by low simple sugar concentration within the embryo)

Question 5

What happens when the GA travels into the Aleurone layer?

Answer 5

Triggers the synthesis of enzymes that will break down the starchy endosperm

Question 6

Why should water sensitive grain have a short initial steep, followed by a longer air rest?

Answer 6

To help the grain achieve a better and more even water uptake during the second water stand

Question 7

What is the typical range of temperature at which the barley grows during steeping?

Answer 7

Water and air temperatures is between 9-16˚C

Air-on temperatures should not exceed 21-23˚C, to avoid damaging the grain.

Question 8

β-Glucanases and xylanases (pentosanases) do what?

Answer 8

Break down the cell walls

Question 9

What does proteases do?

Answer 9

Will break down the protein matrix, as well as the middle lamella.
This exposes the starch molecules, making them accessible for the α- and β-amylases to work on them

Question 10

What type of steeping vessels are there?

Answer 10

Conical

Flat Bottom

Question 11

What type of germination vessels are there?

Answer 11

Saladin Boxes

Circular

Question 12

What is the optimum moisture content after kilning?

Answer 12

3-6%
Standard ale malt = 2-3% moisture
Standard pale malt = 4-6% moisture

Question 13

What is green malt?

Answer 13

Malt at the end of germination

Question 14

Why is green malt kilned for?(5)

Answer 14

Kill embryo but preserve enzymes
Reduce moisture content
Produce unique flavours and colours
Drive off DMS
Create a product than can be easily milled

Question 15

Low temperatures during the initial stages of kilning will preserve more what?

Answer 15

Enzymes

Question 16

What is the Maillard reaction?

Answer 16

The products of germination, the sugars from starch breakdown and the amino acids react, converting them into melanoidins, all react together to eventually give colour and flavour to the malt

Question 17

What are the 3 stages of drying process?

Answer 17

Free drying - Moisture in the husk is removed by warm, dry air at lower temperatures around 50-60˚C (air off)
Forced drying - Moisture falls below 12-13%, temperature rise to 65-75˚C (air on) to force the moisture from the centre of the grain and remove it
Curing -air-on temperature is at its highest. It is > 70˚C, however most of the time it is > 85˚C. Colour and flavour are easily formed

Question 18

What is germinative Energy?

Answer 18

The percentage of kernels that germinate and gives a measure of dormancy.

100 grains are placed on a filter paper in a petri dish in 4mls of water for 72hrs at 18˚C to see a percentage of germination.

Question 19

What is water sensitivity?

Answer 19

The potential of the grain to grow in water - this reflects conditions during steeping

Same as GE but placed in 8ml of water for 72hrs but checking every 24 for corn counts

Question 20

What moisture content can barley be stored at? (before its steeped)

Answer 20

12%

Question 21

What is the typical temperature for steeping and how long is it steeped for?

Answer 21

14 - 16˚C

48hrs

Question 22

What is the typical temperature and duration for germination?

Answer 22

14-20˚C

4-6 days

Question 23

What is Nitrosamine (NDMA)

Answer 23

Carcinogenetic compound usually formed from direct fire in a kiln (the protein hordein react with nitroxide)

Question 24

What is deculming?

Answer 24

Removing the rootlets from the malt after kilning

Question 25

How many air rests are there when steeping and why?

Answer 25

3, so the grain can replenish the oxygen back into the embryo and suck up water more effectively

Question 26

What are some enzymes that can effect brewing?

Answer 26

Lipids
Phenols
Tannins