It will be useful to give here some remarks by the great scientist,
Liebig, on the best process of making bread:--
“Many chemists are of opinion that flour by the fermentation in
the dough loses somewhat of its nutritious constituents, from a
decomposition of the gluten; and it has been proposed to render the
dough porous without fermentation by means of substances which when
brought into contact yield carbonic acid. But on a closer investigation
of the process this view appears to have little foundation.
“When flour is made into dough with water, and allowed to stand at
a gentle warmth, a change takes place in the gluten of the dough,
similar to that which occurs after the steeping of barley in the
commencement of germination in the seeds in the preparation of malt;
and in consequence of this change the starch (the greater part of it in
malting; in dough only a small percentage) is converted into sugar, a
small portion of the gluten passes into the soluble state, in which it
acquires the properties of albumen, but by this change it loses nothing
whatever of its digestibility or of its nutritive value.
“We cannot bring flour and water together without the formation of
sugar from the starch, and it is this sugar and not the gluten of which
a part enters into fermentation, and is resolved into alcohol and
carbonic acid.
“We know that malt is not inferior in nutritive power to barley from
which it is derived, although the gluten contained in it has undergone
a much more profound alteration than that of flour in the dough, and
experience has taught us that in distilleries where spirits are made
from potatoes, the plastic constituents of the potatoes, and of the
malt which is added after having gone through the entire course of the
processes of the formation and the fermentation of the sugar, have lost
little or nothing of their nutritive value. It is certain, therefore,
that in the making of bread there is no loss of gluten.
“Only a small part of the starch of the flour is consumed in the
production of sugar, and the fermentative process is not only the
simplest and best but also the cheapest of all the methods which
have been recommended for rendering bread porous. Besides, chemical
preparations ought never, as a rule, to be recommended by chemists, for
culinary purposes, since they hardly ever are found pure in ordinary
commerce. For example, the commercial crude muriatic acid which it is
recommended to add to the dough along with bicarbonate of soda, is
always most impure, and often contains arsenic, so that the chemist
never uses it without a tedious process of purification for his
purposes, which are of far less importance than making bread light and
porous.
“To make bread cheaper it has been proposed to add to dough potato
starch or dextrine, rice, the pressed pulp of turnips, pressed raw
potatoes, or boiled potatoes; but all these additions only diminish
the nutritive value of bread. Potato starch, dextrine, or the pressed
pulp of turnips, and beet-root, when added to flour, yield a mixture
the nutritive value of which is equal to the entire potato, or lower
still, but no one can consider the change of grain or flour into a food
of equal value with potatoes or rice an improvement. The true problem
is to render the potatoes or rice similar or equal to wheat in their
effects, and not _vice versâ_. It is better under all circumstances to
boil the potatoes and eat them as such, than to add potatoes or potato
starch to flour before it is made into bread, which should be strictly
prohibited by police regulation on account of the cheating to which it
would inevitably give rise.”