A brewery takes the four ingredients: water, hops
, and makes them into beer
. Traditionally, hops came from an oast house
, malt from a maltings
, water from a well, and live yeast from the previous brew.
Stage 1: Mashing
Water (referred to in the trade as liquor, despite the fact that it contains no alcohol at this point) is heated to above 90o
C in a kettle
. Sometimes minerals such as gypsum
are added to alter the mineral content. Pipes feed this hot water into a large vessel called a mash tun
, where milled malt (grist
) and hops are added. The mash tun contains paddles which stir the mash, dissolving the maximum amount of sugars from the malt, and alpha acids
from the hops.
The resulting mash is strained, using additional water to sparge, i.e. wash any remaining sugars from the dregs.
This liquid now referred to as wort (pronounced wurt), is cooled and passed to the fermenting vessel.
Stage 2: Fermentation
Yeast is added to the wort, and left in the fermenting vessel, which can be traditionally rectangular and open to the air - called Yorkshire squares, or enclosed in a cylinder with ventilation at the top. For an ale
, fermentation takes place above ground at room temperature and takes about a week. For a lager
, this takes longer - about a month, and requires chilling to around 5o
Stage 3: Bottling/Casking
One of two processes happens. Either the beer is filtered, pasteurised and carbonated, then put into bottles and kegs
, or isinglass
is added as finings
to precipitate out dead yeast (the finings do not end up in the beer). In this case some sugar is added to assist secondary fermentation or conditioning
, and the beer is put into bottles as bottle conditioned beer
, or casks
as real ale
for distribution to pubs.