Hardwood Ash

The grey-white ash left when clean hardwood burns completely is the starting point for lye and soap, potash, ash glazes and nixtamal, and a garden lime. Its largest part is calcium carbonate, with potassium salts, and it is alkaline: wet ash stings the skin. Only clean wood: never painted, treated, glued or mixed with rubbish. How much ash a load of wood gives varies with the species and how much bark is on it, so weigh both and find out.