How many persons does this recipe serve?
LESSON CXII
LEAVENING WITH BAKING POWDER: GRIDDLE CAKES
EXPERIMENT 72: EFFECT OF COLD WATER ON A MIXTURE OF CREAM OF TARTAR AND
BAKING SODA.—Test a bit of cream of tartar with moistened litmus paper.
Is it acid or alkaline in reaction?
Put 1/8 teaspoonful of baking soda and twice the quantity of cream of tartar in a dry test tube. Does any change take place? Add about 1 teaspoonful of cold water to the mixture and examine. What change takes place? What substance is being formed?
EXPERIMENT 73: EFFECT OF HOT WATER ON A MIXTURE OF CREAM OF TARTAR AND BAKING SODA.—Repeat Experiment 72, using hot water instead of cold with the baking soda and cream of tartar. Which causes greater effervescence,— hot or cold water? Is it desirable to have more of the gas formed before or after the mixture is placed in the oven? What, then, should be the temperature (hot or cold) of liquids and other materials used in the quick bread mixtures?
EXPERIMENT 74: EFFECT OF HOT WATER ON BAKING POWDER.—Add about 1 teaspoonful of hot water to 1/4 teaspoonful of baking powder. Compare the effervescence with that of Experiment 73. From the comparison of Experiments 72 and 73, with Experiment 74, what two kinds of substances do you infer this baking powder contains?
(Save the contents of the tube for the following experiment.)
EXPERIMENT 75: STARCH IN BAKING POWDER.—Filter the contents of the tube used in Experiment 74 through filter paper (see Figure 30). Add a drop of tincture of iodine to the insoluble material left on the filter paper. What is the insoluble constituent of this baking powder?
COMPOSITION OF BAKING POWDER.—Baking powder consists of