Fermentation of Beer
ISPE SF Bay Area Chapter
Pyramid Ale House Tour
presented by Dan McAdam, Bayer HeathCare
Bayer HealthCare, Emeryville
June 24, 2010
History of Beer
„ Beer is one of the world's oldest beverages
dating back to the Neolithic 9000 BC
„ A beer made from rice was probably made in
China around 7000 BC
„ The earliest known chemical evidence of beer
dates to circa 3500–3100 BC from Iran and
Egypt
„ Beer was spread through Europe by
Germanic and Celtic tribes as far back as
3000 BC
Why did people make beer?
„ Utilize excess grain & safeguard the harvest
„ Keep vermin away from harvest
„ Increase the value of the grain harvest
„ Reduce volume of grain
„ Provide a safe source of potable water
„ Bread and beer has been argued to be
responsible for humanity's ability to develop
technology and build civilization
Ingredients
„ Barley
„ Hops
„ H2O
„ Yeast
1st Good Manufacturing Practices
„ German Beer Purity Laws
„
Gave us the 4 sacred ingredients in Beer
„ Before Purity Laws, anything goes in Beer
Exotic preservatives
„ Funny fermentables
„ Whole, raw roosters, YUM!
„
Raw Materials – Malt & Grain
„ Barley Malt
Malt is sprouted the dried barley grain
„ Kiln drying
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Enhances quality – less spoilage
Time and temp impacts the malt
ƒ Dark, roasted longer, hotter
ƒ Light, roasted until dry
ƒ Crystal, Caramel, Roasted, Toasted
Raw Materials - Water
„ Influence of water
„ Famous Beer styles are from certain regions:
why? - It’s the water
Prague
„ Milwaukee
„ Dublin
„ Newcastle
„
Raw Materials - humulus lupulus
„ aka Hops
„ Delicious
„ Preservative characteristics – antimicrobial,
antioxidant
„ Lupulin in hops give the characteristic nose
and flavor
„
Measured as alpha acid – high alpha = hoppy
beer
„ Flavor depends on variety and region
Raw Materials - Yeast
„ Ales (top fermenting) warm and fast
- 60 to 75 degrees F
- 4-20 days
- saccharomyces cereviecea
„ Lagers (bottom fermenting) cool and slow
- 35 to 60 degrees F
- 14 to 90 days
- saccharomyces carlesburgensis
/ pastorianus
What do we do with this stuff?
„ Mill
„ Mash
„ Lauter
„ Boil
„ Cool
„ Pitch Yeast (inoculate)
„ Ferment
„ Clarify
„ Package
„ Enjoy!!! – my favorite
Time to Mash
„ Malted Barley is milled to crack the grain and
increase surface area for mashing – now
called grist (No not grits)
„ Grist is mashed, or steeped at specific
temperatures in steps call “rests”
Protein rest helps solubilize malt proteins
„ Sugar rest is when natural enzymes in malted
barley chop up starch into sugars
„ Larger, non-fermentable and smaller,
fermentable sugars are produced. Ratio
impacts the dryness, EtOH content and “feel”
„
Lautering
„ Like column chromatography
Hot water is gently added to top of mash and
sweet wort is collected
„ This step washes sugars and other
compounds out of the mash
„
Boil
„ Wort is boiled, hops are added
„
Boiling eliminated undesirable things like
„
„
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Beer spoiling organisms – DIE!!
Certain proteins – coagulate into ‘trub”
Compounds in hops – driven off in boil
„ Hot wort is cooled, yeast is added
„ Fermentation begins!
Fermentation
„ Process of deriving energy from the oxidation of
organic compounds, such as carbohydrates
„ Fermentation does not necessarily have to be
carried out in an anaerobic environment
„ Sugars are the most common substrate of
fermentation
„ Yeast added to wort eats sugar molecule and creates
alcohol and CO2 as by products
Controlling the fermentation
„ Add O2 to get yeast started
„ Once started no more O2
„ Control the temperature
„ Too cold = nighty night yeast
„ Too warm = funny taste and HANG-OVER
„
Produces phenolic compound
„ Closed fermentation keeps other bugs away
„ Can cause delicious characteristics like wet
band aid and sweaty gym sock flavors or fuzzy
beer
After Fermentation
„ Beer is matured
„ Sometimes called “Secondary” Fermentation
„ Not much fermenting happens, but beer mellows a bit
„ Beer is ready to package
„ Filtration and/or pasteurization
„ Crystal clear beer, need for carbonation
„ “Live Beer” bottle conditioned, no filtration, small
amount of fermentable sugar added and then
carbonation occurs in sealed container
„ Danger! Live yeast inside – woops, it’s good for you,
great source of vitamin B
Post Fermentation
„ Wort is now Beer
„ Yeast removed and beer clarified and
carbonated
„ Beer may be Pasteurized and /or sterile
filtered
„ Packaging
Economics of Beer
„ Today, the brewing industry is a global
business, consisting of several dominant
multinational companies and many thousands
of smaller producers ranging from brew pubs
to regional breweries
„ 133 billion liters (35 billion gallons), the
equivalent of a cube 510 meters on a side, of
beer are sold per year
„ total global revenues of $294.5 billion
Special Thanks to:
Noah Beery, Brewmaster
Broken Drum Brewery, San Rafael
for the use of his slides