Calcium
stearate is a carboxylate of calcium, classified as a calcium soap. It is a component of some lubricants, surfactants, as well as many foodstuffs.
It is a white waxy powder
Calcium stearate is produced by heating stearic acid and calcium oxide:
2 C17H35COOH + CaO → (C17H35COO)2Ca + H2O
It is also the main component of soap scum, a white solid that forms when soap is mixed with hard water. Unlike soaps containing sodium and potassium, calcium stearate is insoluble in water and does not lather well.[2] Commercially it is sold as a 50% dispersion in water or as a spray dried powder. As a food additive it is known by the generic E number E470