1444 The Cornell Reading-Courses 



The strength of baking powder depends on its ability to produce carbon 

 dioxid. It is essential, therefore, that the mixture of soda and acid be 

 kept dry if the ingredients are not to combine. In order to prevent loss 

 of strength, a drying agent such as starch, which will absorb moisture, 

 is added to the mixture of soda and acid and the baking powder is kept 

 in sealed tin cans or glass jars. 



Types of commercial baking powders 



There are three types of baking powder on the market. All of them 

 contain bicarbonate of soda and starch, and they differ only in the acid 

 constituents. 



Cream-of-tartar baking powder. — The average standard high-priced baking 

 powders contain, as the acid constituent, cream of tartar or tartaric acid, 

 or a mixture of the two. Soda and a dr}'ing agent constitute the other 

 ingredients. 



Phosphate baking powder. — In a second type of baking powder the 

 soda and starch are combined with an acid phosphate, and this type is 

 therefore called phosphate baking powder. 



Alumic baking powders. — The third type of baking powder is the alum 

 powder. If the label on the box of baking powder contains the words 

 " altmiinum " or " alumic," the purchaser may know that an alum baking 

 powder forms the contents of the box. As with the other baking powders, 

 soda and a drying agent form part of the mixture. 



Homemade baking powder 



A very satisfactory baking powder may be made at home after the 

 following recipe: 



\ pound of cream of tartar 



\ pound of soda 



I ounce of cornstarch 



Weigh carefully and mix very thoroughly by shaking the soda and starch 

 together in a tin or glass can. Add the cream of tartar last, and shake 

 again thoroughly and vigorously for several minutes. Or mix all ingredi- 

 ents together and sift twelve times. The secret of success is very thorough 

 mixing of the three ingredients. 



This baking powder deteriorates if kept for any length of time, and 

 should therefore be prepared in quantities small enough to last for only 

 ten days or two weeks. 



Do not attempt to keep baking powder, either commercial or home- 

 made, in a paper bag. It should be placed in a dry tin or glass receptacle, 

 covered tightly, and stored in a dry place. 



