Food Biochemistry and Food Processing

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Table 29.1.

Overview of the Brewing Processing Steps: From Barley to Beer

Process

Action

Objectives

Time

Temperature (°C)

Malting

Steeping

Moistening and

Preparation for the germination

48 hours

12–22

aeration of barley

process

Germination

Barley germination

Enzyme production, chemical

3–5 days

22

structure modification

Kilning

Kilning of the green malt

Ending of germination and modification,

24–48 hours

22–110

production of flavoring and coloring substances

Milling

Grain crushing without

Enzyme release and increase of

1–2 hours

22

disintegrating the husks

surface area

Mashing



wort

Addition of

Stimulation of enzyme action, extraction

1–2 hours

30–72

separation

warm/hot water

and dissolution of compounds, wort filtration, to obtain the desired fermentable extract as quick as possible

Wort boiling

Boiling of wort

Extraction and isomerization of hop

0.5–1.5 hours



98

and hops

components, hot break formation, wort sterilization, enzyme inactivation, formation of reducing, aromatic andcoloring compounds, removal of undesired volatile aroma compounds, wort acidification, evaporation of water

Wort

Sedimentation or

Removal of spent hops, clarification



1 hour

100–80

clarification

centrifugation

(whirlpool, centrifuge, settling tank)

Wort cooling

Use of heat exchanger,

Preparing the wort for yeast



1 hour

12–18

and aeration

injection of air bubbles

growth

Fermentation

Adding yeast, controlling

Production of green beer

, to obtain yeast

2–7 days

12–22 (ale)

the specific gravity,

for subsequent fermentations, carbon

4–15 (lager)

removal of yeast

dioxide recovery