CHARLES D. WINTERS / SCIENCE PHOTO LIBRARY CHARLES D. WINTERS / SCIENCE PHOTO LIBRARY
Editorial use only.
Alum powder. Alum may be used in pickling recipes as a preservative to maintain fruit and vegetable crispness. Alum is both a specific chemical compound and a class of chemical compounds. The specific compound is the hydrated potassium aluminium sulphate (potassium alum). More widely, alums are double sulphate salts.
Model release not required. Property release not available.