Brewing Flashcards
What is the definition of beer?
Carbonated fermented alcoholic beverage made from barley and flavoured with hops
How is fermentation done for brewing?
Batch using monoculture, anaerobic or aerobic
What is the yeast used for beers?
Saccharomyces
What are the 3 steps of making beer?
Malting and wort production
Fermentation
Finishing and packaging
What occurs in the malting and wort production phase?
Conversion of raw materials into fermentable sugars and yeast nutrients
Flavour and colour introduction
What occurs in the fermentation stage?
Growth of yeast on wort
Conversion of sugars into ethanol, CO2 and metabolites
What occurs in the finishing stage?
Adjustments to colour, flavour and carbonation
Made haze and microbe stable
What other materials can be added in beer?
Adjuncts
Roasted malts
Enzymes
What is malting?
Production of key enzymes for brewing
What does malting do?
Breaks down structure of endosperm to generate colour and flavour
What is the malting process?
Storage and drying
Steeping (increase moisture)
Germination (3-5 days)
Kilning (drying)
What is the role of kilning?
Stops germination and degradation of starch and protein
Dires grains
Retain enzymes
Generate colour and flavour
Why is high temperature important for the kilning process?
Provides roasted malt for better flavour and lower grist
What is grist?
Cereals that form starch for brewing
What are some adjuncts used in beer?
Wheat, maize, rice and sugar syrups
What is the role of liquor (water) in beer manufacture?
Flavour, pH and yeast nutrition
How is water altered to gain a desired composition?
Purified and filtered to remove ions then add salt
What is the role of hops?
Bitterness, aroma and microbe stability
Where are hops found?
Resins and oils in lupin glands
When are hops added in the manufacture process?
Late on
How does hops provide a unique flavour?
Contains hydrocarbons and sulphur
What are the operations for wort production?
Grist preparation
Milling
Mashing
Solid and liquid separation
Boiling
Clarification
What is the milling step?
Splitting grain for endosperm accessibility
What is the mashing step?
Mixing grist with water and enzymes for fermentation
What is the difference between alpha amylase and beta amylase?
Beta produces fermentable sugars and is heat sensitive, alpha is opposite
What is the optimum pH for protein solubilisation and enzyme activity in wort production?
5.2-5.4
What is the role of boiling wort?
Boils off volatile compounds and develops flavour and colour by Maillard reaction
Why is beer bitter?
Alpha acids undergo chemical reaction
What is the process of wort clarification?
Proteins are at isoelectric point and become denatured when boiled to form trub
How is trub removed?
Wort is spun and eddy currents produced to allow wort to be drawn away at various points
What is the final step of wort production?
Oxygen is added for yeast growth
