1lb Potassium Aluminum Sulfate

Potassium aluminum sulfate, usually sold as potash alum, supplied food grade as 1 lb of white crystals. It dissolves readily in warm water and gives a mildly acidic solution.

It is used as a coagulant in water treatment, where it flocculates suspended solids so they can be filtered out; as a mordant for natural dyeing on wool and cotton; and as a firming agent in pickling. Gardeners use it as a soil amendment to lower pH. It also appears in astringent and styptic preparations and in leather tanning.