In cooking, these highly astringent crystals of potassium aluminum sulfate were once widely used as the crisping agent in canning pickles. Alum can cause digestive distress, however, and modern canning methods make its use unnecessary.
In cooking, these highly astringent crystals of potassium aluminum sulfate were once widely used as the crisping agent in canning pickles. Alum can cause digestive distress, however, and modern canning methods make its use unnecessary.