What causes occasional color changes in chocolate cakes?
Chocolate cake color is very sensitive to variations in batter pH, which is the result of interactions of various ingredients and variations in pH of these ingredients. In general, the color of cocoa will vary from cinnamon brown at pH 5.0 to a chocolate brown at pH 7.0 and a mahogany at pH 7.5. This change is a result of indicators in the cocoa which change from yellow in acid to red in alkaline medium. Factors that affect pH include cocoa and chocolate ingredients, eggs, flour, and leavening ingredients. Normally, the proper pH can be obtained in chocolate cakes by adjusting the baking soda level to obtain the desired pH.
