There is a vast number of different
beers with a whole range of tastes and strengths. British
brewers alone produce over 2000 real ales and numerous other beers
and lagers. Brewing has been traced back as far as 5000 BC
in the Middle East yet brewing is a complex process requiring
skill and care. If you crush grapes then wine ferments from
it, the juice of apples will turn naturally to cider, but to make
beer from barley requires many steps.
All beer is brewed from malted barley,
hops, yeast and water though other ingredients can be used.
Yeast ferments the sugars in the malt to produce alcohol.
Hops provide bitter flavour and aroma. The flavour of the
beer depends on many things, the types of malt and hops used, the
use of other ingredients and, crucially, the type of yeast
used. Each variety leaves its own distinctive influence on
the beer. The beers served in our pubs fall into two
distinct categories because they are produced in two different
ways. These are Lager and Real Ale.
LAGER AND SMOOTH
This was first produced in Pilsen,
Czechoslovakia in 1842 and uses bottom fermenting yeast, ones
which sink to the bottom of the fermenting vessel.
Fermentation takes place at lower temperatures and should be
followed by a long period of cold conditioning. The beer is
then pasteurized or heated to nearly boiling point to kill off any
live yeast, then filtered to remove the dead yeast cells.
Because they are more susceptible to bacterial infection, they
have to be dosed with stabilizers and preservatives. Finally
they are pumped up with carbon dioxide and nitrogen to replace the
sparkle lost when killing off the live yeast. Because they
are a dead product they are much easier to handle at the pub and
require less skill from the staff.
In the Brewery
This is the beer which has evolved over
many centuries and is known in the trade as cask conditioned ale
or beer. In the brewery the beer is neither filtered nor
pasteurized. Even when the normal brewing process has been
completed it still contains sufficient yeast and sugars for it to
continue to ferment and mature in the cask. Once it has
reached the pub cellar, it has to be laid down for maturation to
continue and for the yeast to settle to the bottom of the
cask. Some Real Ale has extra hops added as the casks are
filled – a process known as dry hopping – giving the beer extra
flavour and aroma.
In the Pub
In the pub cellar, cask beer has to be
nurtured to maturity and condition. Each cask has two holes,
in one of which the tap is inserted and the other allows any extra
gasses produced by secondary fermentation to be released.
However, cellar staff must ensure that sufficient condition is
maintained so that the beer is not served flat. Condition is
maintained by using wooden pegs called spiles in the second hole
to control the level of carbon dioxide in the beer. As real
Ale is a living product it needs care and once the cask is opened
it has a limited shelf life. It has to be consumed within a
few days otherwise it will become flat, cardboard and vinegar
flavours will develop as the beer reacts with oxygen in the
air. It is best served at cellar temperature, which is
around 12-13 C, although some stronger ales can benefit from being
served a little warmer.
After skilful work by pub cellar staff,
real ale that has reached its peak of condition must be
transported from the cask, where it has continued to mature, to
the glass of the customer. There are several ways of
achieving this but the most usual is the familiar hand pump which
is connected to a "beer engine". This is a simple suction
pump which raises beer from the cellar to the bar via the tap on
the cask. Where the cellar is particularly deep an inline
electric pump may be used to aid this transfer.
We are lucky enough to have a huge
variety of Real Ales in this country. They are still being
produced by a very large number of regional brewers. As we
develop this part of the guide we will give the details of the
brewers in each county together with the real ales produced by
Real Ale can be produced to a high
standard on a small scale in the micro breweries.
Some pubs use these micro breweries to
produce beers for their pubs, thereby increasing the numbers of
different ales available.
Original Gravity (OG) is the measure of
‘fermentable material’ (malt sugars and added sugars) taken before
fermentation. It is a rough indication of
Alcohol by Volume (ABV) is a more
reliable measure of the strength of the finished beer. Often
OG’s and ABV are identical i.e. 1035 and 3.5