A brief introduction into the brewing of beer.

1. 1
BEER BREWING

2. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
What is beer?
• Fermented by yeast
• Fermented sugar derived from a cereal starch source
• There are lots of different strengths and styles
• 0 to 20% ABV - Ale, lager, stouts, porters
• Wheat, fruit, spiced, smoked
• Lite beers to pale ales to strong ales
• Doppelbocks, maibocks, schwartz and dunkel
• Kolsch and Dortmund
• Trappist, lambic, gueuze
• Native beers

3. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
Beer is an alcoholic beverage produced from the fermentation of
sugars by yeast to produce alcohol.
Most of the sugar in brewing comes from barley, which has to be
malted to release the sugars before fermentation can occur
DEFINITION OF BEER
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4. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
Beer flavour is derived from..
• Alcohol, residual sugars, hop aroma and bitterness
• Salts
• CO2 or N2
• Esters, higher alcohols
• Dimethyl sulphide ( DMS )
• and a host of other biochemicals measured in ppb

5. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
Beer faults include...
• Stale
• Diacetyl
• Aldehydic
• Sulphury
• Grainy
• Sunstruck
• Phenolic
• Catty
• Acidic
• Metallic

6. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
THE MALTING & BREWING PROCESS
BARLEY MALTING MALT
BREWHOUSE
FERMENTATION
MATURATION
& FILTRATION
PACKAGING
WORT
GREEN BEER
BRIGHT
BEER
CANS & BOTTLES
CASKS & KEGS
WATER
HOPS
Cask

7. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
BREWING MATERIALS
BARLEY
Gibberellic acid
Bromate
MALTING
BREWHOUSE
FERMENTATION
MATURATION
& FILTRATION
PACKAGING
WATER
ELECTRICITY
STEAM
AIR
used
in all areas
HOPS
Leaf
Extracts
Pre Isomerised
Isinglass
Auxiliary finings
Post FV bitterness
Hop aroma
Flavourings
Beechwood chips
pH adjustment
PVPP
Tannic acid
Silica hydrogel
Proteolytic enzymes
Primings
Krausen
Antioxidants
Heading agents
Filter powder
Recovered beer
Salts
Sugars
Coloured malts
Roasted barley
Caramel
Copper finings
Glucanase
Antifoam
Yeast food
Oxygen
ZnSO4
CO2 and N2
Bottles and cans
Ends
Crowns
Hicone
Labels
Shrinkwrap
Glue
Foils
Trays and cartons
Pallets
Casks and kegs
Keg caps
Cask bungs
Dry hops

8. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
CO PRODUCTS and WASTES
MALTING
BREWHOUSE
FERMENTATION
MATURATION
& FILTRATION
PACKAGING
Culms
Screenings
Spent grains
Spent hops
Spent filter cake
Spent alcohol
CO2
Yeast
Packaging waste
Glass cullet
Crushed cans
EFFLUENT IS PRODUCED
BY ALL AREAS
Animal feeding
Distilling
Yeast tablets
Horticulture
Vinegar
Glass paper
Recycling

9. Brewing materials
• Water
• Malt and adjuncts
• Hops and hop products

10. USE of WATER in BREWING
Brewing requires a plentiful supply of good clean water.
Water accounts for approximately 94% of the total beer volume.
Water is used for:
brewing & process dilution  treated brewing water
cleaning & CIP  softened water
bottle washing & past.  mains/untreated water
general cleaning e.g. floors  mains
boiler feed water.  demineralised water

11. To be suitable for brewing, water must be:
• Clear & Colourless
• Tasteless & Odourless
• Not acidic or alkaline ( pH 7 or slight acid )
• Correct salt composition ( varies by beer type )
• Free from residues ( heavy metals, nitrates organic residues ).
• Microbiologically pure ( coliform bacteria absent )
Water Quality - Appearance & Taste.

12. Effect of pH
• Lower pH
•  amylase and peptidases work at optimum pH
• encourages break formation
• less polyphenol extracted from malt and hops leads to cleaner flavour
• less tannins but more protein breakdown gives lower haze potential
• improves foam by reacting with lipids
• in beer discourages the growth of spoilage organisms
• Calcium itself stabilises alpha amylase
• helps precipitate oxalates and
• helps yeast flocculation
• Higher pH encourages
• extraction of undesirable polyphenols from the last runnings from the mash
• increases hop utilisation
• increases colour formation

13. Barley is the principal source of carbohydrate.
The energy is stored as starch in the endosperm
Enzymes, produced during malting, convert starch to sugar.
Malt.
PRINCIPAL RAW MATERIAL - BARLEY

14. Malting barley
• Variety should be approved for malting. It should be short strawed to counter wind
damage and give a good yield per hectare
• There is always a trade off between adding nitrogenous fertilisers to increase yield
but with a protein content unsuitable for malting
• The more protein, the less starch so the brewer gets a lower extract from his mash
• The more protein, the more prone the beer to haze formation and the more amino
acids etc available to beer spoilage organisms
• Brewers talk of nitrogen levels.
Protein = nitrogen x 6.25 so 1.5% nitrogen = 9.4% protein
• In the UK there is a malting premium.
• Lighter chalky soils will not retain added nitrogen so produce the best malting barley

15. Each individual batch of barley should be assessed prior to malting for:
• Uniform size and colour
• Bold grain with few screenings ( smaller corns )
• Freedom from smell, mould growth and insects
• No admixture with other cereals or barley varieties
• Absence of split skinned or pre-germinated grains
• Moisture - freshly harvested around 18% - storage at 12%
• Capable of growing with a germinative capacity greater than 95%
• Total nitrogen less than 1.8%
• for some barley used to produce ale malt the total nitrogen should be below
1.6%.
BASIC REQUIREMENTS OF A MALTING BARLEY VARIETY.

16. Malting is a controlled germination
process
• Steps of malting:
• Steeping
• mimics the corn getting wet and growth starts
• Germination
• under controlled conditions
• Kilning
• arrests growth by killing the embryo but temperatures are carefully
controlled so that enzymes are not denatured ( inactivated )
• Colour and flavour compounds develop

17. Other malted cereals
• Any starch source can be malted
• Can be used to impart subtly different flavours
• Oats
• enhance dryness - oatmeal stouts
• Rye
• Increase palate fullness at high levels but rye has no husk so wort run off can be
difficult
• Wheat
• At 4% addition will improve head retention with no effect on flavour
• Wheat beers at up to 60% wheat have a dry refreshing clovey taste

18. Adjuncts
BREWING WITH ADJUNCTS
Adjuncts come in two forms
• Solid starch adjuncts which have to be converted to sugar in the brewhouse during
mashing
• Malt enzymes convert the starch to sugar
• May require heat treatment to gelatinise or liquefy the starch to allow enzymes to
convert it
• Liquid adjuncts are already in the form of sugar
• Conversion from starch has taken place at the suppliers plant
• The sugars are ready for fermentation but are generally added directly to the kettle so
they benefit from sterilisation.
• Usually derived from maize, different acid and enzyme treatments can produce different
fermentabilities

19. ADVANTAGES OF USING ADJUNCTS
• Cost and availability
• Control of fermentability
• Colour and flavour contribution
• Beer presentation
• Process benefits/development
– Increased brewing capacity through shorter brewing cycles and
more uniform wort quality.
– Ease of handling and usage
– Cleaner fermentation - better yeast heads
– Improved hot and cold breaks
– Shorter maturation times.

20. TYPES of LIQUID ADJUNCTS
Cereal Syrups -
• Produced with various sugar compositions
• Direct source of extract added to the copper
Raw Sugars -
• Cane sugar is the principal component in most primings
• Invert sugar a mixture of glucose and fructose syrup,
( liquid or solid block form ).
Priming Sugars
• Add sweetness, fermentability or colour after the end of primary fermentation & to act as a
source of sugar for a secondary fermentation.
Colouring Products -
• Hot water extracts from roasted and coloured malts
• Caramel produced by the controlled heating of food grade sugars with ammonia
• Class 3 - Ammonia caramel is used for brewing - must not react with beer component to form
hazes:

21. Hops
FUNCTION of HOPS in BREWING
• Hops provide the bitter taste in beer (with alpha acid the principal
precursor)
• The oils provide aroma.
• Hops contribute to beer texture (mouthfeel)
• Hops have bacteriostatic properties which protects beer against some
biological spoilage organisms.

22. FUNCTION of HOPS in BREWING
• Hops reduce over foaming during wort boiling.
• Hops aid in protein coagulation during the boil.
• Hops are a foam active agent in beer.

23. 23
The brewhouse receives the malt and uses the natural enzymes
produced in the malt to convert the starch to sugar.
The sugar solution ( wort ) is separated from the solids, boiled to
increase its stability along with hops which add bitterness and flavour
to the beer.
The boiled wort is clarified and cooled, from where it goes on to act
as the nutrient for yeast to fuel the fermentation.
Purpose of Brewhouse operation.

24. 24
THE BREWING PROCESS - BREWHOUSE
Milling
Malt
Mash Conversion
Water
Mash Separation
Wort Boiling
Adjunct
(optional extra)
Wort Clarification
Wort Cooling
Hops
Oxygen
Co-products
Malt dust
Spent grains
Trub
Cold wort
fermentation

25. 25
Purpose: to expose the extract for conversion.
Students should have a basic knowledge of the key stages of milling.
• They should understand the reason for milling.
• Know and describe one type of mill.
• Know the grist composition for one type of mash separation
system.
• Be familiar with hazard and safety requirements when milling.
Milling

26. 26
BREWHOUSE PROCESS - MILLING
OBJECTIVE:
Malt is received from the maltsters and stored (usually in silos on site).
Before brewing the malt has to be milled which involves splitting the husk and
grinding the endosperm into small grits.
It is necessary to keep the husk as whole as possible since it will be used to form
the filter bed during run off.
The endosperm must be broken down to allow the enzymes to attack the starch.
• Too coarse grind - poor extract & starch carry-over.
• Too fine grind - run off problems & set mash.

27. 27
Purpose: to mix the ground malt with a set amount of water at a given
temperature thus allowing the natural enzymes from the malt to
convert the starch in the endosperm to sugar.
Students should have a basic knowledge of the steps in mashing. They
should:
• Understand the changes which occur to the malt during mashing.
• Know the times and temperatures of the mashing regime
• Be able to define when mashing is complete
• Be able to describe a mash mixing vessel
Mashing

28. 28
Mashing
• To mix the crushed grain evenly with the correct amount of water at
the correct temperature
• To allow other additions such as brewing salts and enzymes to be evenly
mixed in
• To allow the enzymic conversion of protein to amino acids and starch
into simpler sugars in the correct amounts to give consistent
fermentation and the right %ABV and Original Gravity
• To extract colour and flavour from any coloured malts and adjuncts
used

29. 29
Enzymes involved in mashing
Amylases - alpha & beta - convert starch to sugar
Proteases - break proteins to peptides & amino acids
Beta glucanase - degrades beta glucans
The factors which control the enzyme activity are
TIME
TEMPERATURE
ACIDITY - pH

30. 30
BIOCHEMISTRY - PROTEIN BREAKDOWN
H N AA AA AA AA AA AA OO H
2
2 3
2 1 n-1
n-2
aminopeptidase carboxypeptidase
n
Endo-peptidase
Exo-peptidase
Mechanisms for Enzymic attack of proteins and polypeptides
Produces:
Proteins - insoluble precipates in spent grains & break
Polypeptides - foam & haze
Amino Acids - yeast growth

31. 31
BREWING PROCESS - MASHING
During mashing the ground
malt is mixed with water at
a specific temperature to
allow the enzymes to
convert the starch to sugar.
It normally takes about an
hour to convert all the
starch and completion can
be checked with the Iodine
test.

32. 32
Purpose: once all the starch has been converted to sugar and dissolved in
water (wort) it has to be separated from the solid material – husk and
acrospire etc.
Students should have a basic knowledge of the steps in mash separation.
They should:
• Know the operation of one type of wort separation system.
• Know the principle elements of control – flow rate, pressure, wort
haze, etc.
• Know the principle factors which effect extract recovery.
• Be able to describe a mash separation vessel
Mash Separation

33. 33
BREWHOUSE PROCESS - WORT
SEPARATION
OBJECTIVE:
Wort separation involves filtering the wort (sugar solution) through a filter bed
made up of the spent husk material.
The purpose is to produce clear bright worts free from solids, it is also important
not to extract compounds such as polyphenols and lipids from the husk.
Effective Wort separation Means:
• High extract recovery (around 98% to 100%)
• Bright worts - free from suspended solids
• Worts free of starch.

34. 34
Types of wort clarification systems
The three principal methods:
• Mash Tun
• Lauter Tun
• Mash Filter
Use the same basic principals:
• Husk material acts as filter bed
• Filter bed supported by screen or plates.
• Strong worts extracted first followed by sparge water to wash
out remaining extract.
• Extraction flow is controlled to maximise clarity and extract
recovery.

35. 35
BREWING PROCESS - SEPARATION
The sugar solution ( wort ) has to be
removed from the spent grains. It is
filtered through a bed made up of the the
husk from the malt.
Wort must be clear and produced with
minimum effluent. Oxygen should be
excluded
In ale breweries filtration is carried out in
the same vessel as mashing - the mash tun.
In modern breweries a separate lauter tun
or mash filter for wort filtration.
The solids left behind are called spent
grains and are fed to cattle.

36. 36
Purpose – to stabilise the wort and to extract and isomerise the bitter
compounds from hops.
Students should have a basic knowledge of the process of wort boiling.
They should
• Know the reasons for wort boiling.
• Know the principle elements of control – time, temperature, vigour
etc.
• Know the principle factors which effect hop utilisation and to be
able to calculate a hop charge.
• Be able to describe a wort boiling system.
Wort Boiling

37. 37
WORT BOILING
After wort separation the clarified wort is boiled.
Hops and sugar adjunct (if required) are added at this stage
Wort boiling is the most energy intensive stage of the brewing process. Not only
does the wort have to reach boiling point, but it is usual to evaporate between 5 and
10% of the kettle contents.
A successful boil must be vigorous.
Usually 60 -90 minutes

38. 38
BOILING
The clarified wort is boiled for about an
hour in a kettle or “copper”
Hops are added during the boil to provide
bitterness and aroma.
Boiling also improves the physical (haze)
stability of the beer and kills any micro-
organisms which could infect the beer and
cause flavour problems.

39. 39
BENEFITS OF WORT BOILING
• Inactivation of malt enzymes
• Sterilisation of the wort
• Extraction and isomerisation of compounds derived from hops
• Coagulation of proteinaceous material in the wort
• Formation of proteinaceous/polyphenol complexes
• Formation of flavour and colour complexes.
• Fall in wort pH
• Concentration of the wort gravity through evaporation of
water.
• Evaporation of volatile compounds from the wort.

40. 40
Control of dimethyl sulphide - DMS
DMS has a sweetcorn flavour and is a component of finished lagers.
Excess quantities are undesirable
DMS is formed from the breakdown of DMS precursor (S-methyl
methionine) from malt due to heating.
DMS is highly volatile and is rapidly lost during boiling.
It build up during the hot wort stand and this should be kept to a
minimum if DMS control is required.
S-methyl methionine DMS BOILING
½ life 35 minutes HEAT
DMS is volatile and is readily removed from beer during boiling.
Formation of DMS during wort boiling.

41. 41
KETTLE ADDITIONS
Main addition is hops - various forms
• At beginning of boil - for bitterness only
• 15 - 5 min. from end - hop aroma - late hopping
• Pre-isomerised hops added towards end of boil
• Hops help prevent over foaming
• Syrup adjunct & colour added early in boil - avoid burning
caramelisation on heating surfaces
• Kettle finings to improve break added 5 minutes before the end of boil.
(Carragheen /Irish Moss - seaweed)
• Mineral salts or acid to adjust wort acidity pH

42. 42
Purpose – to separate the coagulated protein (trub) and hop debris
from the hot wort.
Students should have a basic knowledge of the process of wort
clarification.
• They should know reasons for wort clarification.
• The effects on duration on quality.
• The use of kettle finings.
• Describe a wort clarification system.
Wort Clarification

43. 43
BREWHOUSE PROCESS - FUNCTIONS
OF WORT CLARIFICATION
The principal changes during hot wort clarification:
• Coagulation of protein/polyphenol complexes.
• Precipitation and separation of hot break
• Temperature dependent chemical reactions started in the boil continue
during the hot stand in the wort clarification stage, e.g. colour formation
& oxidation.
• Temperature dependent reactions which produce flavour active volatiles
(e.g. DMS) can build up as they can not be removed in a vigorous boil.

44. 44
KETTLE FININGS ADDITION TO A
STANDARD BOILED WORT
Addition of kettle finings improves the settlement of solids and the clarity of the
wort. Best results occur with maximum settled solids and brightest (lowest) cold wort
haze.

45. 45
Purpose: to cool the clarified wort after boiling prior to fermentation.
Candidates should have a basic knowledge of wort cooling. They should
know
• Mechanisms for wort cooling.
• Typical cold wort temperatures for ale and lager beers
• Reasons for aeration
• About the formation of cold break.
• About microbial risks.
Wort Cooling

46. 46
FUNCTIONS OF WORT COOLING
The clarified wort has to be cooled to the fermentation
temperature.
Wort cooling is carried out using a heat exchanger.
The cooling medium is brewing water which is recovered ( as
warm water ) for the following brew.
For low temperature cooling involves a glycol or cooled water
stage.
Wort is oxygenated on the cold side

47. 47
BREWING PROCESS - COOLING
After boiling the protein and
hop debris precipitates have
to be removed. They are often
mixed with the spent grain.
The hot sugar solution (wort)
is then cooled to the required
temperature for
fermentation.
Yeast is added to the cool
wort along with a small amount
of air or oxygen to promote
vigorous growth at the start
of fermentation.

48. 48
ADDING OXYGEN
• Usually on the cold side
• to avoid colour pick up
• hot side if aerating will sterilise the air
• Aeration will add around 8ppm O2
• Oxygen must be used for higher gravity worts
• More gas dissolves in colder and lower density liquids
• Gas must be sterile and dissolve before reaching the fermenter

49. 49
OTHER ADDITIONS
• Nutrients
• Zinc sulphate or yeast foods
• Enzymes
• Antifoam
• Salts

50. 50
KEY POINTS FOR BREWHOUSE
• The stored malt is ground to produce “grist”.
• During mashing the grist is mixed with an appropriate amount of brewing
water to produce a mash at pre-set temperature (or temperatures).
• The mash is allowed to stand until all the starch from the malt is converted to
sugar.
• The sugar solution (called wort) is then separated from the malt solids, during
wort separation.
• Wort separation occurs in a single vessel or Mash Tun in traditional ale
breweries. A two vessel system – mash mixer with either a lauter tun or mash
filter is used for lagers.
• The collected wort is boiled with hops. It is clarified (hot break removed) and
cooled ready for fermentation.

51. Microbial contamination
 Bacteria - very small organisms, only a very limited range live in
beer - pathogens will not survive in beer
 Wild Yeast - organisms of the same basic type as brewing yeast
but giving rise to flavour defects in beer
 Fungi/Moulds -organisms similar to yeasts growing in old beer or
unclean containers

52. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
Potential for contamination
• Raw materials
• Taints, pesticide residues, grain weevils. Mycotoxins
• Dust, wood etc in cans, plastic in crowns and can lacquer
• Broken glass
• Water supply
• Nitrates, spillages, trihalomethanes
• Plant cleaning
• Residual detergent, residual chlorine
• Poor road tanker cleaning
• Process
• Coolant ingress via plate heat exchanger leaks
• Plastics
• Oil or grease
• Microbiological.

53. INSTITUTE &
GUILD OF
BREWING
GENERAL
CERTIFICATE IN
BREWING &
PACKAGING
2001
Water borne contamination
• Pathogens will not grow in beer
• Pathogens will grow in water
• Water must be checked for pathogens eg Escherichia Coli, the presence will indicate
sewage contamination
• Other coliforms can adapt to life in a non hygienic brewery. All can reduce nitrate to
nitrite but do not survive in finished beer
• Legionella can also exist in mist sprays in air conditioning systems
• Cryptosporidium
Water borne protozoan - causes diarrhoea
Destroyed by boiling but not by chlorine
Does not live in beer