Dr. Lek Wantha

Beer Brewing

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Beer… Alcoholic beverage Fermented gains

Barley Wheat corn millet

Alcohol: 0.5-8 % alc. /w pH : 4.3 Sugar : 1.12% Protein: 0.33% CO2 :2.27%/vol.

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Beer Types… Lager

Bock Munich Pilsner

Ale Porter Stout Wiss

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Lager vs Ale beersLager Ale

Relatively new Thousands of years old

Fermented cold Fermented warm

Bottom fermentation Top fermentation

Yeast – Saccharomyces uvarum Yeast – Saccharomyces cervisiae

Longer brew cycle - up to several months

Quick brew cycle - as little as 7 days

Usually brewed between 4-13 ºC Usually brewed between 15-25 ºC

Smoother, crisper, and more subtle in taste and aroma

Strong, assertive, and more robust in taste

Served cold, 4-7 ºC Served not too cool, 10-14 ºC

(source: http://www.beer-faq.com/difference-ale-lager/)

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Materials Brewing Water Barley Malts Malt Adjunct Hops Yeast

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Materials: Brewing Water

90% of beer is water pH 7.5 50-100 mg/l CaCO3

55 mg/l of total water hardness <25 mg/l of permanent water hardness

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Materials: Barley Malts

Six-row barley Two-raw barley

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Materials: Malt Adjuncts

unmalted grains Corn Rice Rye Oats Barley Wheat

lower cost carbohydrate modify the flavor of beer

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Materials: Hops

Hop constituents %

humidity 12.5

ash 7.5

cellulose 13.3

aroma oil 0.4

tannin 3.0

total nitrogen 17.5

non nitrogen extract

27.5

Ether extract 18.3

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Materials: Yeast

top-fermenting Saccharomyces cerevisiae

bottom-fermenting Saccharomyces pastorianus Saccharomyces carlsbergensis Saccharomyces uvarum

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Brewing Process Malting Malt Milling Mashing Brewing Wort Boiling Fermentation Maturation Filtration Carbonation Pasteurization

Malting

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Beer Brewing

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Defect… Physical factors

Turbidity Light temperature

Biological factors Microorganism

Bacteria Acetobacter Lactobacillus pastorianus Flavobacterium proteus Bad smell (Hydrogen sulfide)

Zymomonas mobilis

Chemical factors Chemical reaction

protein

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References…

Goldammer, Ted. The Brewer’s handbook. http://www.beer-brewing.com/index.htm