92 / 154
92
A TREATISE ON
ture of the wort when it is added, differ in different
brew~ries
and for different kinds of beer. From
i
to
1! of yeast, taken from a previous brewing of the
same kind of beer, is the quantity usually employed.
The higher the temperature the less yeast necessary.
In
England, the temperature at which the yeast is
usually added, varies from 55° to 65° Fahr.
In
cold
weather, the heat in the coolers should be 5° to 6°
higher than in mild and warm weather. For ale, in
cold weather, it should be tunned as soon as it has
fallen to 60° in the coolers. For porter, to 64°, and
for table beer to 70° ; and in warm weather, strong
beer should be 4° or 5° less, and table beer 7° or 8°.
Care should be also taken that the worts do not get
cold before the yeast is mixed to produce fermenta–
tion. The common rule for mixing the yeast is
li
lbs. to every barrel of strong beer wort, and 1 lb.
to every barrel of table beer wort.
The commencement of the fermentation is indica–
ted by a line of small bubbles round the sides of the
tun, which, in a short time, extends over the surface.
A crusty head follows, and then a fine rocky one,
followed by a light frothy head. In the last stage,
the head assumes a yeasty appearance, and the color
is yellow or brown, the smell of the tun becoming
strongly vinous. As soon as this head begins to fall,
the tun should be skimmed, and the skimming con-
Digitized
by