what is powdered alum
Alum powder is a crystalline powder that is most commonly used in pickling; it keeps pickles firm and crispy.THIS ALUM WILL NOT GROW CRYSTALS. Alum powder is often used to firm and crispen pickles by letting them soak in a sealed brine solution of water, vinegar, salt, spices, and alum powder for several weeks.lum powder is often used to firm and crispen pickles by letting them soak in a sealed brine solution of water, vinegar, salt, spices, and alum powder for several weeks.