Self-Assessment Questions

1. *Indicate whether the following statements are true or false. If false, provide a reason why you think this.

(a) The main parameters that indicate malt quality are:

  • Moisture
  • Colour
  • Modification
  • Enzyme activity
  • Visual assessment
  • Food safety

(b) During malt analysis, DP and DU refer to enzyme levels.

(c) Calcofluor stain is used to determine the total nitrogen level in malt.

(d) An acrospire growth greater than one, indicates over-modification.

2. *Name the three governing bodies that develop and govern the methods used for malt analysis.

3. *Name two analyses that can be used to determine total and soluble nitrogen.

4. *How would you convert 85 ˚Lintner to a ˚WK number?

5. *List the most important characteristics that brewers want from their malt.

6. *Explain the parameters friability and homogeneity. Why are they important for the brewhouse?

7. **List the three factors that influence extract recovery in the brewhouse concerning barley malt. Explain why.

8. **You are asked to buy malt for your brewery. Refer to the CoA for Malt A and B, and answer the following questions:

Table: Malt CoA 1 & 2

Parameter

Unit of measure

Specification

Malt A

Malt B

IOB

EBC

EBC

EBC

Moisture

%

4.5-5.5

4.5-5.5

4.3

4.2

Extract yield (dry wt)

l°/kg or %

>305 l˚/kg

>80.5%

79.50%

79.80%

Corn size >2.5mm

%

95

95

98.37

96.8

Colour

EBC

2-4

2-4

3.9

4.15

Total nitrogen

%

1.6-1.8

1.6-1.8

1.6

1.64

Total soluble nitrogen

%

0.57-0.66

0.65-0.75

0.63

0.70

FAN

mg/l

>160

>160

180

173

SNR

%

34-40

38-44

39 KI

41

Friability meter reading

%

>85

>85

87.7

86.5

Homogeneity

%

>96

>96

96.36

96

Diastatic power

WK

>65˚ IOB

>222 WK

454

375

Wort viscosity

mPas @ 20˚C

1.55-1.65

1.55-1.65

1.49

1.52

DMS-p

mg/kg

2-8

2-8

2.65

2.65

Beta glucan

mg/l

<200

<250

84

150

Additional information

 

 

 

 

 

Acrospire 0-1/4

%

 

 

6

1

Acrospire 1/4-1/2

%

 

 

1

5

Acrospire 1/2-3/4

%

 

 

1

4

Acrospire 3/4-1

%

 

 

90

86

Acrospire >1

%

 

 

2

4

NDMA ppb

ppb

 

 

0.5

0.5

*Aflatoxin B1, B2, G1 & G2, ppb

ppb

 

 

0

0

Foreign Seeds

%

 

 

0

0
  • (a) Assess the β-glucan level. Do you think this will cause issues during the brewing process?
  • (b) Explain the difference between total and soluble nitrogen.
  • (c) Convert the total nitrogen for Malt A into protein amount.
  • (d) How may a low nitrogen value affect the brewing process?
  • (e) Describe the process of analysing acrospires.

9. ***You receive additional information on Malt B. It is a blend of two pieces, and the results of their analysis using EBC methods are shown in the CoA below. Please answer the following questions:

Parameter

Unit of measure

Specification

Malt

Results

IOB

EBC

B

Piece 1

Piece 2

Moisture

%

4.5-5.5

4.5-5.5

4.2

3.9

4.5

Extract yield (dry wt)

l°/kg or %

>305 l˚/kg

>80.5%

79.80%

80.8

78.8

Corn size >2.5mm

%

95

95

96.8

96.4

97.2

Colour

EBC

2-4

2-4

4.15

4.4

3.9

Total nitrogen

%

1.6-1.8

1.6-1.8

1.64

1.62

1.66

Total soluble nitrogen

%

0.57-0.66

0.65-0.75

0.70

0.7

0.69

FAN

mg/l

>160

>160

173

180

166

SNR

%

34-40

38-44

41

44

38

Friability meter reading

%

>85

>85

86.5

88

85

Homogeneity

%

>96

>96

96

98

94

Diastatic power

WK

>65˚ IOB

>222 WK

375

430

320

Wort viscosity

mPas @ 20˚C

1.55-1.65

1.55-1.65

1.52

1.48

1.56

DMS-p

mg/kg

2-8

2-8

2.65

2.65

2.65

Beta glucan

mg/l

<200

<250

150

100

200

Additional information

 

 

 

 

 

 

Acrospire 0-1/4

%

 

 

1

1

1

Acrospire 1/4-1/2

%

 

 

5

0

10

Acrospire 1/2-3/4

%

 

 

4

4

4

Acrospire 3/4-1

%

 

 

86

91

81

Acrospire >1

%

 

 

4

4

4

NDMA ppb

ppb

 

 

0.5

0.5

0.5

*Aflatoxin B1, B2, G1 & G2, ppb

ppb

 

 

0

0

0

Foreign Seeds

%

 

 

0

0

0

(a) Critically evaluate Piece 2.

(b) Would you purchase Malt B for your brewery? Explain why.

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