Formation of Colour and Flavour

Compounds in Crystal Malt

Ross Turner | PureMalt Products LtdMBAA

Saturday 7th June 2014

Agenda

1. Introduction to Crystal Malt

2. Crystal Malt Production

3. Maillard Reaction Principles

4. Colour and Flavour Development

5. Quality: ‘Good vs Bad’ Crystal Malt

6. Summary

Introduction to Crystal Malt

• Crystal malt is used in both brewing and food manufacturing• Crystal malt addition to beer

typically 1-20%• Utilised for both colour and

flavour enhancement• Wide variety of crystal malts

available with varying intensities of colour and flavour profiles

Crystal Malt Specification: (Typical ranges)

Colour: 20-400 EBCExtract: 75-80%Moisture: 4.5-6.5%pH: 4.8-5.2

Probat Roaster

Introduction to Crystal Malt

• Produced from Green Malt• High moisture content >46%• High protein content up to 13%• High germination temperature 20°C• Good homogeneous modification!

• Two stage batch production process:• Stewing

(Gelatinisation/Saccharifaction)• Roasting

(Maillard/Caramelisation)

Stage Temperature Time

Stewing 60-80°C 20-60mins

Roasting 135-180°C 80-100mins

0 20 40 60 80 100 120 1400

20

40

60

80

100

120

140

160

0

10

20

30

40

50

60

70

80Temperature Profi le:

Crystal Malt Production

Product Temperature

% Moisture

Time (mins)

Tem

pera

ture

Moi

stur

e %

Stewing phase Roasting phase

Crystal Malt Production: Stewing

• In-Kernel ‘mashing’ process• Gelatinisation, liquefaction and

saccharification takes place• Diastatic & Proteolytic enzyme activity• Starch degradation to sugars• Protein degradation to amino acids

• 60-80°C temperature is optimal for enzyme activity

• Roasting Drum is sealed to retain moisture• Highly modified Green Malt becomes ‘wort’

equivalent inside kernel! Enzymic activity during stewing

Drum Conditions:

60-80°C 20-60mins

Crystal Malt Production: Roasting

• Colour and flavour formation through:• Maillard Reactions• Caramelisation Reactions

• Process variables:• Time• ‘Joe’ Factor! (artisanal operator impact)• Temperature• Moisture content

• Moisture reduction to 3-4%• Enzyme inactivation

Drum Conditions:

135-180°C 80-100mins

Maillard Reaction Chemistry

Amino Acids

Reducing sugars

Heat

Melanoidins & Flavour

compounds

• Two states of Maillard reactions in crystal malt production• Aqueous reactions (water acts as solvent)

• Solid-State (pyrolysis)

• Produce different flavour impressions depending on amino acid involved• Accelerated by high protein

content malt, high temperatures and low pH.

Crystal Malt Specifications: Flavour Formation

Compound Odour Characteristics

Concentration in Crystal Malt

Methylpyrazine Popcorn, Nutty, Cocoa 0.10

2- Furaldehyde (furfural)

Bread, Almond, Sweet 0.78

Isomaltol Burnt Sugar, Fruity 5.11

2- Furanmethanol Bready, Estery, Sweet 21.0

Maltol Caramel 155

DDMP Candy, Cookies 28.2

Crystal Malt: Flavour Formation

Compound Symbol

Methyl-Pyrazine

Isomaltol

DDMP

2-Furaldehyde

2-Furanmethanol

Maltol

Maillard Reaction: Colour Formation

Malt Type Colour (EBC)

Colour (Lovibond)

Cara 2.5-6.5 1.5-3

Caramalt 25-40 10-15

Premium Caramalt

45-60 17-23

Crystal Light 80-100 30-37

Crystal 130-160 50-60

Crystal Dark 200-230 75-86

Crystal 400 400-440 150-165

Time

Tem

pera

ture

Good vs Bad Crystal Malt

Homogeneous Crystal Malt Un-homogeneous Crystal Malt

Time

Tem

pera

ture

Crystal Malt Sensory Profile

200°C

180°C

160°C

140°C

120°C

100°C

80°C

60°C

40°C

20°C

0°C

Candy

Cookie/Nutty

Toffee

Caramel

Acknowledgements

Many thanks to…

David Cook

Philip Robbins

Erika Trauth

Ross Turner

PureMalt Products Ltd.

Ross.Turner@PureMalt.com