Aluminum is added to baking soda that belongs to a category called double-acting. This type of baking soda undergoes one reaction when the baking soda is mixed with the other ingredients and releases carbon dioxide and another reaction that releases more carbon dioxide when the product is being baked. The second reaction is activated by the heat during the baking process due to the addition of aluminum compounds.
The addition of aluminum makes baked products lighter and ensures that they rise more, even if the mixture of ingredients is placed in the oven after a considerable amount of time. But the presence of aluminum compounds in the baking powder gives an odd taste to many dishes and aluminum is also being linked to Alzheimer’s disease now. This has led many people to opt for aluminum-free baking powder.