k. In London the manager of a "tied" shop is
usually held to account for 92 loaves to the sack.

In the _ferment and dough_ system, the ferment usually consists of 10 to
14 lb. of potatoes to the sack of flour, boiled or steamed, and mashed
with water, so as to yield about 3 gallons of liquor. There are several
substitutes for potatoes, including raw and scalded flour, malt, malt
extracts, &c.; brewers' or distillers' yeast may also be used. A ferment
should contain saccharine matters and yeast stimulants in such a form as
to favour the growth and reproduction of yeast in a vigorous condition.
Hence it should not be too concentrated. About six hours are required
for its preparation. It is added, together with 2 to 3 lb. of salt, to
the dough, which is prepared with about 56 quarts of water to the sack,
and worked at a temperature of 80-84 deg. Fahr. The dough is allowed to
lie from two to five hours according to the flour used, the character of
the ferment, and the working temperature. In this system the proportion
of strong flour is usually reduced to 40% of the dough, and no doubt in
some cases only soft or weak flours are used. Naturally the yield of
bread is not so high as in the case of an off hand dough made entirely
from strong flour, and it will probably not exceed 90 loaves to the
sack. This method has many advantages. After the ferment is made the
labour required is not much greater than with the off hand doughs, and
less yeast is required, while potatoes, which are somewhat troublesome,
from the necessary cleaning, can be replaced by the substitutes already
mentioned. The method produces good-looking and palatable bread, though
the loaves should be eaten within some twelve hours of leaving the oven.

The _sponge and dough_ system, which is probably in widest use in
England, is adapted to almost every kind of bread, and has the advantage
that any kind of flour can be employed. The stronger flours which need
long fermentation can be and usually are used in the "sponge" stage,
while soft flours are utilized in the dough. (The sponge is a certain
proportion, varying from a quarter to one-half, of the flour necessary
for making the batch.) In London the baker often uses for the sponge a
bag (140 lb) of American spring wheat flour, and for the dough a sack
(280 lb) of British milled flour, which, whether it be country flour
milled largely from English wheat or London milled, is always softer and
weaker than that us