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How Beer is Made
P r 4-5 persona duhen:
by Sara Doersam
Beer making dates back to 5,000 BC when yeast was discovered
fermenting in a sugar-water mixture. The yeast consumes the
sugar for its own energy and growth, and the primary byproducts
are ethyl alcohol and carbon dioxide. Wine is made when yeast
consumes the natural sugars in fruit such as grapes, and beer
is made when yeast consumes the sugar derived from grain.
The naturally occurring starch found in grain must be converted
into sugar before yeast can consume it. Thus, beer making is
a more complex art than wine making.
Making beer can be broken down into two separate processes
-- malting and brewing --
usually performed by two separate businesses.
Malting is the processing and preparation of grains
for brewing and takes years of training and experience
to master. Malting begins by soaking grain, usually barley,
in water long enough to begin germination or sprouting.
At the same time, enzymes are developing which break
down starches to sugars. The grain is then heated in
a large oven, called a kiln, which arrests germination
and stops the growth of the grain. Other grains, such
as wheat, rye, and oats can be malted, and many maltsters
sell malted wheat which is commonly used in several
specialty styles of beer.
Most homebrewers do not make their own malt because
it takes one to two weeks, requires close monitoring
and much work, and frequently renders inconsistent
results. The two most common methods of malting are
the traditional floor malting method, where grain is
literally spread across the floor to germinate, and
pneumatic malting, most common today, where the
environment is strictly controlled inside tanks or drums.
Maltsters can malt grains for a wide variety of
different types of malt, each offering a different
flavor and character.
Beer has four main ingredients
-- malt,
water,
yeast,
and hops
-- and it can be as simple or technically challenging
to brew, as down home cooking is compared to gourmet
cuisine. Each ingredient has its own equally
important role to play in the production of beer.
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P rgatitja:
To brew beer, the brewer begins by weighing the appropriate
amount of grain for his recipe. He then mills his malt in a
malt mill which cracks his grain. In commercial operations,
the milled malt drops into a grist case which has a valve
at the bottom which allows the grain to drop through a
chute into the mash tun. Usually homebrewers simply
collect their milled grain in a clean container and
dump it into their mash tun. The mash tun is a large
vessel, usually made of copper or stainless steel,
that has a screen-like false bottom for straining
your mash later.
Mash is a thin mixture of grains and hot water.
Mashing is the process of heating grains mixed
with water at controlled temperatures for
designated periods of time to activate enzyme
activity that converts starches to fermentable
sugars. Converting starches to sugars is called
saccharification. There are three common mashing
methods. Infusion mashing is the simplest because
it involves only one temperature throughout the
mashing process. Step infusion mashing is basically
infusion mashing with one or two temperature increases
during mashing. And decoction mashing, most commonly
used for lager style beers, is the most complex method
because part of the mash is removed and boiled,
then reintroduced.
Once mashing is completed, the brewer must separate
the sugar-water, called wort, from the spent grain husks.
He does this by sparging or rinsing the spent grains with
hot water to extract as much sugar from the grains
as possible. The grain husks act as a filter bed on
the false bottom of the mash tun. Commercial brewers
usually do their sparging in a lauter tun. After the
wort is collected in the brew kettle, it is boiled
for one to two hours.
The boil is a critical step in the brewing process because
it is at this step that hops, the aromatic flowers of hop vines,
are added. Hops impart aroma, flavor, and bitterness to beer,
which balances the sweetness of the wort. To extract
the bitter resins from hops they must be boiled, and
usually hops are added at various stages of the boil
to extract bitterness or impart aroma or flavor.
When the boil is completed, the hot wort is transferred
to a heat exchanger or wort chiller which rapidly drops
the temperature of the wort to about 80 degrees
-- fermentation temperature.
As the tepid wort exits the wort chiller, it goes into
a fermenter where yeast is added. Most homebrewers us a
large glass called a carboy or stainless steel kegs for
fermenting, but commercial brewers use huge stainless
steel cylindrical conical tanks for fermenting.
The main genus of yeast used by brewers is Saccharomyces,
and the species used to make ales is a top fermenting strain
called cerevisiae, while the species used to make lagers
is a bottom fermenting strain called uvarum. The type of
yeast used during fermentation determines whether a beer
is an ale or a lager.
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The yeast sets to work eating the malt sugar and expelling
alcohol and carbon dioxide. This usually takes three to
seven days and is referred to as primary fermentation.
Homebrewers then rack or transfer the beer off of
the yeast bed and into a secondary fermentation vessel,
whereas commercial brewers drain the yeast that
has collected out of the bottom of the tank.
If lagering, the beer may remain in cold storage for
several weeks or for a shorter period and in warmer
temperatures if brewing an ale. During the secondary
fermentation, the yeast precipitates out of suspension,
carbonation develops, and the beer matures.
Finally, the homebrewer is ready to bottle or keg his
beer for serving, while the commercial brewer may filter
the beer to make it bright and clear before kegging,
bottling, or transferring it into a serving tank.
Homebrewing is one of the fastest growing hobbies.
If you can follow a recipe, you too can brew.
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