balance the acidity of dark malts that
normally extract too much astringent material
from barley husks, and encouraged the
development of dark German beers and
British porters and stouts.
Boiling the Wort Once the liquid wort has
been drawn off the grain solids, the brewer
runs it into a large metal tank, adds hops, and
boils it vigorously for up to 90 minutes.
Boiling converts the insoluble hop alpha acids
into their soluble form and develops the
beer’s bitterness, and inactivates the barley
enzymes and so fixes the carbohydrate mix —
a certain portion of sugar for the yeasts to
convert into alcohol, a certain portion of
dextrins for the beer’s body. It sterilizes the
wort so that the brewing yeasts won’t have
any competition during fermentation, and it
concentrates the wort by evaporating off some
of its water. Boiling deepens the wort’s color
by encouraging browning reactions, mainly