Can baking soda be used as a substitute for powdered alum in pickles?

Baking soda should not be used as a substitute for powdered alum in pickles.

Powdered alum (potassium aluminum sulfate) is commonly used as a firming agent in preserving pickles due to its astringent properties. Baking soda, on the other hand, is primarily used as a leavening agent due to its alkaline properties and would generally not provide the same effect.