PowerPoint Presentation - Art of Brewing

1
The Art of Brewing and The Biology of Lager Yeast
Tom Pugh Miller Brewing Company
2
Purpose

• Provide a better understanding of...
• The brewing process
• Types of brewing yeasts
• Attributes important to the brewer

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
3
The Art of Brewing
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
4
Definition of Beer

• An alcoholic beverage produced by the
  fermentation of sugar-rich extracts derived from
  cereal grains or other starchy materials.

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
5
History of Brewing

• Man has been making beer since the dawn of
  civilization.
• Where grain was grown, beer was made.
• Sumaria (4000 BC) Sikaru
• Egypt (3000 BC) Zythum
• India (2000 BC) Sura
• China (2000 BC) Kiu

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
6
History of Brewing

• Sumarian beer recipe
• 3000 BC
• Resembled liquid bread
• Barley and Emmer
• Spices / fruits
• No Hops
• Safe, nutritious, and exhilarating beverage.

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
7
The Role of Yeast in Brewing

• Unwittingly, ancient brewers domesticated yeast.
• Selected yeast that made good beer.
• Deduced that yeast was important to make beer.
• Collect the creamy foam or sediment from one
  brew.
• Use it to pitch the next brew.

Did not know what yeast was.
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
8
The Role of Yeast in Brewing

• 1680 Antonie van Leeuwenhoek
• Observed yeast in beer.
• 1837 - Cagniard Latour
• Microbe is responsible for alcoholic
  fermentation.
• 1839 -Justus von Liebig and Friedrich Wohler
• Alcohol is produced by a chemical process in
  which dead and decaying yeast participated.
• Satired Latours theory in Annalen der Chemie . .
  .

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
9
.small animal which sips sugar through its
snout, and excretes alcohol from its gut and
carbonic acid from its urinary organ.
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
10
The Role of Yeast in Brewing

• 1866 - Louis Pasteur
• Yeast was responsible for alcoholic fermentation.
• 1883 - Emil Christian Hansen
• Developed pure culture technique
• Isolated pure cultures of brewing yeasts

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
11
Brewing Yeasts
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
12
Types of Brewing Yeasts

• Two types of brewing yeasts, originally
  classified on flocculation behavior
• Top-fermenting
• Ale yeast
• Weiss yeast
• Bottom-fermenting
• Lager yeast

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
13
Weiss
Ale
Lab
Lager
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
14
Ale Yeast

• Predominant brewing yeast prior to the mid-1800s.
• Displaced by lager yeast
• Strains are genetically more diverse - several
  origins
• Warm fermentation temperatures 65 to 72 F.

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
15
Weiss Yeast

• Bavarian origins - closely related.
• Produces beer that has spicy, clove, vanilla, and
  nutmeg flavor notes - POF.
• PAD1 gene phenylacrylic acid decarboxylase
• Decarboxylation of ferulic acid forms
  4-vinyl-guaiacol, which gives the characteristic
  clove flavor.
• Warm fermentation temperatures 65 to 72 F.

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
16
Lager Yeast

• Bavarian origin.
• 1400s in Munich - cool fermentations (selective
  pressure)
• Taken to Pilsen and Copenhagen in 1840s
• Pale malt, soft water, aromatic hops
• Became very popular - displaced ale yeast
• Popularity fueled by advances of Industrial
  Revolution
• Steam power, refrigeration, railroads,
  pasteurization and filtration technology
• Strains are closely related - common origins
• Cool fermentation temperatures 42 to 52 F
• Beers are more delicate, clean, drinkable, and
  less aromatic.

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
17
Taxonomy

• Ale and Weiss yeasts - Saccharomyces cerevisiae
• Polyploid and probably aneuploid.
• Non-mating
• Sporulates poorly and poor spore viability
• Lager yeast - Saccharomyces pastorianus
• S. cerevisiae
• S. carlsbergensis
• S. uvarum
• Sporulates very poorly - poor spore viability

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
18
Distinguishing Characteristics

• Colony morphology
• Microscopic appearance
• Chain formation
• Fermentation characteristics
• Flocculation behavior / flavor compound profiles
• Growth at 37 C
• Melibiase
• Electrophoretic karyotyping

Yeast 37 C Melibiase POF Lager -
- Ale - - Weiss -

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
19
Distinguishing Characteristics

• Difficult to distinguish between different lager
  yeasts using conventional techniques
• Colony and cell morphologies similar
• Fermentation characteristics
• PCR - limited success
• Electrophoretic karyotyping

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
20
Genome Structure - Lager Yeast

• Allopolyploid and probably aneuploid.
• Tetraploid
• Natural hybrid
• S. cerevisiae and S. bayanus
• S. cerevisiae and S. monacensis
• Contains two types of chromosomes
• S. cerevisiae type
• S. bayanus type

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
21
Genome Structure

• Gene order and function highly conserved
• Single chromosome transfer experiments
• Gene length similar, but nucleotide divergence.
• Low levels of recombination between homeologues

Nt. Identity
AA. Identity
Gene
ILV1 86 96 ILV2 85
92 MET2 84 94 URA3 79 93
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
22
Electrophoretic Karyotypes
cerev.
parad.
Lager
Ale
Lab
Weiss
Lager
Ale
Lab
bayan.
pastor.
XII
XII
IV
IV
XV, VII
XV, VII
XVI, XIII
XVI, XIII
II, XIV
X
II, XIV
XI
X
V
XI
VIII
V, VIII
IX
IX
III
VI
III
VI
I
I
T
C
C
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
23
The Brewing Process
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
24
Ingredients

• Malted barley
• Cereal Adjunct
• Hops
• Water

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
25
Malted Barley

• Two types of barley
• 2-rowed
• 6-rowed
• Provides fermentable sugars, flavor, and color.
• Malting process
• Steeping
• Germination
• Kilning
• Purpose
• Activate enzyme systems
• Preserve for brewhouse

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
26
Steeping

• Soak, aerate, drain.
• 2 days

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
27
Germination

• Ventilated to remove CO2
• Repeated turning
• 4 to 5 days

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
28
Cereal Adjuncts

• Types of adjuncts commonly used
• Corn grits
• Rice
• Corn syrups (high maltose and dextrose)
• Purpose
• Additional source of fermentable sugars
• Lighter body

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
29
Hops

• Spice of beer
• Provides aroma and bitterness
• Flower (cone) of a vine-growing plant
• Humulus lupulus
• Female triploid
• Used as
• Whole cones
• Pellets
• Extracts

Lupulin Glands
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
30
Hops
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
31
The Brewing Process
Step
Purpose
Starch
Brewhouse
Sugars
Wort production
Ethanol
Sugars
Fermentation
Flavor production
Carbonation Flavor maturation
Lagering
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
32
The Brewing Process
Malt Mill
Cereal Cooker
Mash Tun
Brink
Fermentation
Lauter Tun
Brew Kettle
Hops
Aeration
Lagering
Hot Wort Receiver
Wort Cooler
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
33
Mash Tun / Cereal Cooker

• Activate malt enzymes
• Convert starch to fermentable sugars

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
34
Lauter Tun

• Strainer

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
35
Brew Kettle

• Sterilization
• Protein coagulation
• Hop extraction
• Volatile removal

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
36
The Brewing Process
Malt Mill
Cereal Cooker
Mash Tun
Brink
Fermentation
Lauter Tun
Brew Kettle
Hops
Aeration
Lagering
Hot Wort Receiver
Wort Cooler
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
37
Wort CompositionCarbohydrates
73 Fermentable
Fermentable
Non-fermentable
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
38
Wort CompositionFermentable Sugars need to
adjust to normal wort
Maltose
Maltotriose
Glucose
Fructose
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
39
Wort CompositionAmino Acids ( adjust to normal
wort)
Arg
Phe
Asp
Leu
Met
Asn
Gln
Ala
Glu
Gly
Lys
Pro
Thr
Tyr
Val
Ser
His
Ile
Not included Cys (2 ppm) and Trp (50 ppm)
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
40
The Brewing Process
Malt Mill
Cereal Cooker
Mash Tun
Brink
Fermentation
Lauter Tun
Brew Kettle
Hops
Aeration
Lagering
Hot Wort Receiver
Wort Cooler
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
41
Fermentation

• Yeast growth
• Alcohol and CO2

• Flavor compounds
• Large - 600,000 L

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
42
Lagering

• Carbonation

• Off-flavor reduction

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
43
The Brewing Process
Malt Mill
Cereal Cooker
Mash Tun
Brink
Fermentation
Lauter Tun
Brew Kettle
Hops
Aeration
Lagering
Hot Wort Receiver
Wort Cooler
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
44
Balanced Growth

• Yeast growth affects beer flavor.
• Need balance between yeast growth and beer
  flavor.
• The brewer needs...
• Desired flavor profile in desired time.
• Sufficient yeast crop for subsequent
  fermentations.
• Oxygen is growth limiting nutrient.
• Control point

Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
45
Yeast Metabolism During Fermentation
Sugars
Oxygen
Membranes
Glucose
CO2
Energy
Unsaturated Fatty Acids Sterols
Esters
Pyruvate
Ethanol
Higher Alcohols
TCA Cycle
Amino Acids
Acetaldehyde
VDK
Organic Acids
Sulfur Volatiles
Amino Acids
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
46
Higher Alcohols

• Formed by the decarboxylation and reduction of
  a-keto acids.
• From amino acid anabolism and catabolism.

Alcohol Amino Acid a-keto acid Isoamyl
Leucine a-keto-isocaproate Amyl Isoleucine a-
keto-3-methylvalerate Isobutanol Valine a-keto-
isovalerate Propanol Threonine a-keto-butyrate
Alcoholic, solventy, and fruity flavor notes
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
47
Esters

• Closely linked to lipid metabolism - growth.
• Reaction of an alcohol and fatty acid
  intermediate
• Acetate esters
• Ethyl acetate solventy, fruity, sweet
• Isoamyl acetate banana
• Phenethyl acetate roses, honey, apple
• Fatty acid esters
• Ethyl caproate apple, aniseed
• Ethyl caprylate apple
• Isoamyl decanoate tropical fruits

Fruity flavor notes
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
48
Vicinal Diketones
Pentanedione
Threonine
a-ketobutyrate
a-acetohydroxybutyrate
Isoleucine
Valine
pyruvate
a-acetolactate
Diacetyl
Buttery, butterscotch flavor
Kindly provided by Tom Pugh and David Ryder of
Miller Brewing Company
49
Thanks to David Ryder of Miller Brewing
Companyand Tom Pugh, formerly of Miller Brewing
Company,for providing this presentation to the
Saccharomyces Genome Databasefor dissemination
to the yeast community.