Modification analysis continued

Question 1

What does the fine/coarse difference in malt indicate?

Answer 1

Indicates how well modified the malt is

A smaller difference indicates better modification.

Question 2

What is the fine coarse difference percentage for well modified malt?

Answer 2

0-0.5%

A difference greater than 1.5% indicates lower than desired modification.

Question 3

What does Cold Water Extract (CWE) test measure?

Answer 3

The amount of extract available from the malt without enzyme action

It provides a guide to the extent of modification.

Question 4

What are acceptable CWE figures expressed as a percentage of malt’s dry weight?

Answer 4

15-22%

This indicates a well-modified malt.

Question 5

How is friability measured?

Answer 5

Using a friabilimeter with 50 g of malt

The crushed material is weighed and compared to the initial weight.

Question 6

What classifications are used to assess mealiness in kernels?

Answer 6

• Mealy
• Half-glassy
• Glassy

These indicate the level of modification.

Question 7

How is the percentage of wholly unmodified grains (% WUG) calculated?

Answer 7

By weighing the grains left on the roller sieve and multiplying by two

This is part of the homogeneity analysis.

Question 8

What does the acrospire growth analysis indicate?

Answer 8

The extent of modification during germination

It can also serve as an index of modification.

Question 9

What does a majority of acrospires in the 0-1/4 range indicate?

Answer 9

Kernels are either dead or growing slowly

This suggests poor modification.

Question 10

What are the implications of the indices of modification in brewing?

Answer 10

They affect extract recovery, wort separation, and beer quality

Understanding these indices is essential for brewers.

Question 11

What problems can insufficiently modified malt cause?

Answer 11

• Poor extract recovery
• Increased viscosity
• Filtration issues

Due to undegraded β-glucans and excessive undegraded protein.

Question 12

What issues can over modified malt cause?

Answer 12

• Higher losses from dust extraction
• Wort separation problems
• Inadequate beer body

Over modification can also block mill rollers.

Question 13

Fill in the blank: The cold water extract test is conducted at _______.

Answer 13

20˚C

Question 14

True or False: Friability indicates how easy it is to crush the malt.

Answer 14

True