session 17-19 Flashcards
hops 3 factors important to brewing
Total Resins, Essential Oils, Tannins
Wort boiling converts the insoluble alpha acids to
a soluble form
Iso-alpha acids are the main
bittering compounds
Essential oils are responsible for
hop aroma
Hydrocarbons are very volatile and
Hydrocarbons are very volatile and do not survive boiling (dry hopping)
Oxygenated fractions are less volatile and
more aromatic (late hop aroma)
Hop deterioration happens trough oxidation and polymerisation of
of α- and β-acids (cheese and rancid
α-acids are not very soluble and bitter.
true
Iso-alpha acids provide more bitterness than
Iso-alpha acids provide more bitterness than Alpha acids
UK typical hop flavour
sylvan
North American typical hop flavour
citrus and estery
european typical hop flavour
floral and spicy
4 and 8 liters of water are required to make one liter of beer
true
Ca2+, Mg2+are minerals that create
hardness
Total hardness is expressed as mg/l of calcium carbonate (CaCO3)
true
Temporary water hardness is caused by the presence of
by the presence of calcium and magnesium hydrogen carbonates
Permanent hardness is due to the presence of sulfate, chloride, and nitrate salts of calcium and magnesium
true
Excessive carbonate hardness (alkalinity) is
undesirable
Noncarbonate hardness is
desirable
HGB produces
increase levels of esters
two anions responsible for water alkalinity are
carbonate(CO3)
and
bicarbonate(HCO3)
The most important fermentation parameters include t
fermentation parameters include wort composition, temperature, oxygenation and yeast management
Higher Alcohols may be produced by
Higher Alcohols may be produced by amino acid catabolism or via carbohydrate metabolism
The important higher alcohols in beers are:
The important higher alcohols in beers are: isobutanol, n-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol
Excessive concentrations of carbonyl compounds cause
stale flavour in beer
Acetaldehyde - accumulates during the period of
of active yeast growth
Diacetyl and 2,3-pentanediones are by-products of the pathways leading to the formation of
the formation of valine and isoleucine
increase in - and - will result in higher levels of alcohol during fermentation
yeast growth and wort aeration
Saccharomyces pastorianus is
lager yeast
yeast cells reproduce through a process called
budding
