Potash refers to potassium compounds and potassium-bearing materials, most commonly potassium carbonate. The word "potash" originates from the Middle Dutch "potaschen", denoting "pot ashes" in 1477.
The old method of making potassium carbonate () was by collecting or producing wood ash (the occupation of ash burners), leaching the ashes, and then evaporating the resulting solution in large iron pots, which left a white residue denominated "pot ash". Approximately 10% by weight of common wood ash can be recovered as potash. Later, "potash" became widely applied to naturally occurring minerals that contained potassium salts and the commercial product derived from them,.
The following table lists a number of potassium compounds that have "potash" in their traditional names: