What are the differences between Clabber Girl and Rumford Baking Powders?

Baking Powders differ in their reaction to moisture and heat depending on their formulation. Rumford Baking Powder’s reaction is approximately 70% with moisture (or in the bowl) and the rest when heat is applied. Clabber Girl’s reaction is approximately 40% with moisture and the rest when heat is applied. Some people prefer the Rumford brand because it does not contain the acid ingredient sodium aluminum sulfate.