Potassium aluminum sulfate, commonly known as potash alum, is a chemical compound with the formula KAl(SO₄)₂·12H₂O. It appears as a colorless or white crystalline solid and is often used in various applications, including water purification, food processing, and as a mordant in dyeing fabrics. This compound is soluble in water and has astringent properties, making it useful in cosmetics and personal care products. Additionally, it plays a role in the production of certain types of paper and is sometimes used in baking as a leavening agent when combined with other ingredients.