Carbon dioxide. Under the United States Food and Drugs Act, the
following definition for baking powder was formulated, "Baking powder is
the leavening agent produced by the mixing of an acid reacting material
and sodium bicarbonate with or without starch or flour.
"It yields not less than 12 per cent of available carbon dioxide."
The principal reason for adding starch to baking powder is for a
standardizing agent. To some extent it also absorbs moisture, thus lessen-
ing the gas lost during storage by reaction of the ingredients and for a
standardizing agent. The federal standard requires 12 per cent of available
carbon dioxide, but most of the baking powders made for home use yield
14 per cent of carbon dioxide. Starch is added to each type of baking
powder in amounts so that 100 grams of the powder yield 14 per cent
carbon dioxide. If the amount of gas produced by a definite weight of
baking powder were not standardized there would be great difficulty in
substituting some types of powders for others in recipes. For under these
conditions the amount of carbon dioxide produced by a teaspoon of powder
would vary far more than it does when the powder yields 14 per cent of
carbon dioxide.
The carbon dioxide of baking powders is classified as total, available,
and residual. The total carbon dioxide is all the carbon dioxide contained
in the powder and may be obtained by using acid with it. The residual
carbon dioxide is that remaining in the powder after water has been mixed
with it and heat has been applied. Available carbon dioxide represents the
difference between total and residual and is the amount usually obtained
under baking conditions.
Types of baking powders. The alkaline ingredient of all baking
powders is soda. The acid ingredient varies, and the names of the various
TYPES OF BAKING POWDERS 451
types of baking powders refer to the kind of compound used for the acid
ingredient. The function of the acid salt is the same regardless of the type
of salt used. It combines with and releases the CO2 from the soda. The
types of baking powders are (1) tartrate, (2) phosphate, (3) sulfate, and
(4) a combination of sulfate and phosphate.
Tartrate powders. The tartrate powders on the market consist of cream
of tartar or a combination of cream of tartar and tartaric acid. Tartaric
acid is not used alone in baking powders. The objections to using it alone
as given by Hart are that "Its reaction is rapid and complete in cold water,
and its keeping quality correspondingly poor." Cream of tartar reacts more
slowly than tartaric acid but keeps and aerates well.
The residue left from cream of tartar and soda is ''Rochelle" salts. See
the reaction under cream of tartar. Tartaric acid leaves sodium tartrate as
a residue.
^2C4H406
+
2NaHC03
>
Na2C4H40c
+ 2H2O
-f- 2CO2
tartaric
soda
sodium
water
carbon
acid
tartrate
dioxide
Page 368
Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
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Carbon dioxide. Under the United States Food and Drugs Act, the
following definition for baking powder was formulated, "Baking powder is
the leavening agent produced by the mixing of an acid reacting material
and sodium bicarbonate with or without starch or flour.
"It yields not less than 12 per cent of available carbon dioxide."
The principal reason for adding starch to baking powder is for a
standardizing agent. To some extent it also absorbs moisture, thus lessen-
ing the gas lost during storage by reaction of the ingredients and for a
standardizing agent. The federal standard requires 12 per cent of available
carbon dioxide, but most of the baking powders made for home use yield
14 per cent of carbon dioxide. Starch is added to each type of baking
powder in amounts so that 100 grams of the powder yield 14 per cent
carbon dioxide. If the amount of gas produced by a definite weight of
baking powder were not standardized there would be great difficulty in
substituting some types of powders for others in recipes. For under these
conditions the amount of carbon dioxide produced by a teaspoon of powder
would vary far more than it does when the powder yields 14 per cent of
carbon dioxide.
The carbon dioxide of baking powders is classified as total, available,
and residual. The total carbon dioxide is all the carbon dioxide contained
in the powder and may be obtained by using acid with it. The residual
carbon dioxide is that remaining in the powder after water has been mixed
with it and heat has been applied. Available carbon dioxide represents the
difference between total and residual and is the amount usually obtained
under baking conditions.
Types of baking powders. The alkaline ingredient of all baking
powders is soda. The acid ingredient varies, and the names of the various
TYPES OF BAKING POWDERS 451
types of baking powders refer to the kind of compound used for the acid
ingredient. The function of the acid salt is the same regardless of the type
of salt used. It combines with and releases the CO2 from the soda. The
types of baking powders are (1) tartrate, (2) phosphate, (3) sulfate, and
(4) a combination of sulfate and phosphate.
Tartrate powders. The tartrate powders on the market consist of cream
of tartar or a combination of cream of tartar and tartaric acid. Tartaric
acid is not used alone in baking powders. The objections to using it alone
as given by Hart are that "Its reaction is rapid and complete in cold water,
and its keeping quality correspondingly poor." Cream of tartar reacts more
slowly than tartaric acid but keeps and aerates well.
The residue left from cream of tartar and soda is ''Rochelle" salts. See
the reaction under cream of tartar. Tartaric acid leaves sodium tartrate as
a residue.
^2C4H406
+
2NaHC03
>
Na2C4H40c
+ 2H2O
-f- 2CO2
tartaric
soda
sodium
water
carbon
acid
tartrate
dioxide