potassium aluminum sulphate, combined with water of crystallization,
K AL (S0J2 12 (H20). The so-called "alum" of baking powder is a
different thing and is more properly named sodium aluminum sulphate,
being a mixture of sodium sulphate and aluminum sulphate, both of them
harmless and non-toxic. It contains neither potassium nor water of
crystallization. The term alum has been used for this article on baking
powder labels at the request of some food commissioners who felt that
this word would be better understood by the common people as showing
in a general way the character of the substance. Unfortunately, it has
had the very different effect of misleading the public into the
erroneous idea that it actually is the alum of commerce and of medicine —
a mistake of which certain manufacturers have not failed to take advan-
tage in decrying baking powder containing alum.
It is prepared by mixing solutions of two sulphates, sodium sulphate
and aluminum sulphate, concentrating the mixture and fusing the result-
ing dried mass. This leaves a mixture which for our present purposes
we may designate by the formula :
Na Al (SO.),
Sodium Aluminum Sulphate
There is no potassium in this substance at all, as there is in the
common alum, and no ammonia as in the less common ammonium alum.
Starch
We also find that besides the soda and the "acid," starch is used in
baking powder. This starch is corn starch of the highest grade of purity
and specially prepared for food purposes.
The starch serves three purposes, two of which play an important
part in keeping the baking powder from spoiling, while the third adds
to the efficiency of its use.
FIRST : It separates the soda from the acid or acid acting salt and
thus by mechanically separating them retards such chemical action as
could be brought about by moisture. The air always contains moisture.
This is very noticeable on rainy days, but it escapes attention in fair
weather. Not only is carbon dioxide set free when water or milk is poured
on the baking powder, but even the moisture in the air gradually causes
the change. Moisture from any source thus spoils the powder.
SECOND : Starch absorbs water and thus prevents moisture from
bringing the active ingredients in contact with each other. In this way
it aids materially in keeping the powder from spoiling. Starch is, for
these reasons, a necessary ingredient of baking powders, and most
especially necessary in the case of straight phosphate baking powders,
which, even when starch is present, deteriorate very rapidly.
THIRD: Starch also dilutes the strength of the baking powder,
so that it may be made to produce the amount of gas desired for efficiency
and for convenience in household methods of measurement.
35
LESSON No. 2 Domestic Science
The laws of ai ew States require that a baking powder shall produce
at least 10% of its weight of carbon dioxid gas. Almost all baking
powders are made stronger than this. The majority of those .upon the
market yield 12% of gas, while the best produce between 14% and 15%.
White of Eggs
Page 15
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
potassium aluminum sulphate, combined with water of crystallization, K AL (S0J2 12 (H20). The so-called "Alum" of baking powder is a different thing and is more properly named sodium aluminum sulphate, being a mixture of sodium sulphate and aluminum sulphate, both of them harmless and non-toxic. It contains neither potassium nor water of crystallization. The term alum has been used for this article on baking powder labels at the request of some food commissioners who felt that this word would be better understood by the common people as showing in a general way the character of the substance. Unfortunately, it has had the very different effect of misleading the public into the erroneous idea that it actually is the alum of commerce and of medicine — a mistake of which certain manufacturers have not failed to take advantage in decrying baking powder containing alum.
It is prepared by mixing solutions of two sulphates, sodium sulphate and aluminum sulphate, concentrating the mixture and fusing the resulting dried mass. This leaves a mixture which for our present purposes we may designate by the formula :
Na Al (SO.),
Sodium Aluminum Sulphate
There is no potassium in this substance at all, as there is in the common alum, and no ammonia as in the less common ammonium alum.
Starch
We also find that besides the soda and the "acid," starch is used in baking powder. This starch is corn starch of the highest grade of purity and specially prepared for food purposes.
The starch serves three purposes, two of which play an important part in keeping the baking powder from spoiling, while the third adds to the efficiency of its use.
FIRST : It separates the soda from the acid or acid acting salt and thus by mechanically separating them retards such chemical action as could be brought about by moisture. The air always contains moisture. This is very noticeable on rainy days, but it escapes attention in fair weather. Not only is carbon dioxide set free when water or milk is poured on the baking powder, but even the moisture in the air gradually causes the change. Moisture from any source thus spoils the powder.
SECOND : Starch absorbs water and thus prevents moisture from bringing the active ingredients in contact with each other. In this way it aids materially in keeping the powder from spoiling. Starch is, for these reasons, a necessary ingredient of baking powders, and most especially necessary in the case of straight phosphate baking powders, which, even when starch is present, deteriorate very rapidly.
THIRD: Starch also dilutes the strength of the baking powder, so that it may be made to produce the amount of gas desired for efficiency and for convenience in household methods of measurement.
LESSON No. 2 Domestic Science
The laws of ai ew States require that a baking powder shall produce at least 10% of its weight of carbon dioxid gas. Almost all baking powders are made stronger than this. The majority of those .upon the market yield 12% of gas, while the best produce between 14% and 15%.
White of Eggs