Potassium dihydrogen phosphate is an inorganic compound with the chemical formula KH₂PO₄. It is deliquescent and melts into a transparent liquid when heated to 400°C, solidifying into an opaque glassy potassium metaphosphate upon cooling. It is stable in air, soluble in water, but insoluble in ethanol. Industrially, it is used as a buffer and culture agent, as well as a flavoring agent in the synthesis of sake, a raw material for producing potassium metaphosphate, and a culture agent, fortifier, leavening agent, and fermentation aid for brewing yeast. In agriculture, it is used as a high-efficiency phosphorus-potassium compound fertilizer.