Magnesium Carbonate is the only other substance at present used
for the purpose of furnishing carbon dioxid gas. The heat of the oven
is not sufficient in this case to cause all the gas to be set free. Magnesium
carbonate is a very light powder. One pound will occupy as much space
as six pounds of soda. The purpose of those who Use this ingredient
in the manufacture of baking powder is mainly to add to the bulk of
the powder and thus make the thoughtless purchaser believe she is getting
raore^ for her money.
Other Substances Necessary-
It will be seen from what has just been said, that none of these car-
bonates are, of themselves alone, satisfactory for baking purposes. Some-
thing else is necessary.
If one has ever dropped a little vinegar on some soda, he has noticed
that a gas was set free. This is carbon dioxide gas. Vinegar contains
an acid, acetic acid, and it is the action of this acid upon the soda that
sets free the gas. Any soluble acid will have this same action on soda,
hence, if we unite such an acid with the carbonate, soda, we have the
necessary substances with which to produce carbon dioxid gas.
The Acid Substance
For the making of baking powder, both acid and carbonate, how-
ever, must be dry substances, and not liquid, like acetic acid of vinegar.
The acid should also dissolve in water. There are many such dry acids,
most of them organic substances. Citric acid, the principal acid con-
tained in lemons, is one of these. Tartaric acid is another.
Beside the true acids, there are some salts which have an acid nature
and which are called acid salts. Of these, calcium acid phosphate, com-
monly called acid phosphate, is one, and potassium acid tartrate, com-
monly known as cream of tartar, is another. There are some salts which
are not acid salts (inasmuch as all of the hydrogen atoms of the acid
have been replaced by a metal) which nevertheless act as very weak
acids. The most common of these is sodium aluminum sulphate, some-
times called "Alum."
Any of these three kinds of substances, the acid, the acid salt, or
the salt with acid properties, acts upon soda and sets free carbon dioxid
gas. The action takes place almost as quickly as the "acid" or salt
dissolves. These substances just mentioned, acid phosphate, "Alum,"
tartaric acid and cream of tartar, together with the soda, are the active
33
LESSON No. 2 Domestic Science
"principles in baking powder. In addition to these there is generally a
quantity "of starch and sometimes dried white of egg. Soda has been
studied. The other substances must€iow be considered.
Tartaric Acid and Cream of Tartar
Page 13
Presented as published in 1916. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
Magnesium Carbonate is the only other substance at present used for the purpose of furnishing carbon dioxid gas. The heat of the oven is not sufficient in this case to cause all the gas to be set free. Magnesium carbonate is a very light powder. One pound will occupy as much space as six pounds of soda. The purpose of those who Use this ingredient in the manufacture of baking powder is mainly to add to the bulk of the powder and thus make the thoughtless purchaser believe she is getting more for her money.
Other Substances Necessary- It will be seen from what has just been said, that none of these carbonates are, of themselves alone, satisfactory for baking purposes. Something else is necessary.
If one has ever dropped a little vinegar on some soda, he has noticed that a gas was set free. This is carbon dioxide gas. Vinegar contains an acid, acetic acid, and it is the action of this acid upon the soda that sets free the gas. Any soluble acid will have this same action on soda, hence, if we unite such an acid with the carbonate, soda, we have the necessary substances with which to produce carbon dioxid gas.
The Acid Substance
For the making of baking powder, both acid and carbonate, however, must be dry substances, and not liquid, like acetic acid of vinegar. The acid should also dissolve in water. There are many such dry acids, most of them organic substances. Citric acid, the principal acid contained in lemons, is one of these. Tartaric acid is another.
Beside the true acids, there are some salts which have an acid nature and which are called acid salts. Of these, calcium acid phosphate, commonly called acid phosphate, is one, and potassium acid tartrate, commonly known as cream of tartar, is another. There are some salts which are not acid salts (inasmuch as all of the hydrogen atoms of the acid have been replaced by a metal) which nevertheless act as very weak acids. The most common of these is sodium aluminum sulphate, sometimes called "Alum."
Any of these three kinds of substances, the acid, the acid salt, or the salt with acid properties, acts upon soda and sets free carbon dioxid gas. The action takes place almost as quickly as the "acid" or salt dissolves. These substances just mentioned, acid phosphate, "Alum," tartaric acid and cream of tartar, together with the soda, are the active
LESSON No. 2 Domestic Science
"principles in baking powder. In addition to these there is generally a quantity of starch and sometimes dried white of egg. Soda has been studied. The other substances must now be considered.
Tartaric Acid and Cream of Tartar