Potassium acetate is the potassium salt of acetic acid, the acid in vinegar. It is a white powder that readily absorbs moisture, made by neutralising acetic acid with a potassium base. INS 261 covers potassium acetates: sub-index (i) names potassium acetate itself, while 261 (ii) is potassium diacetate. In the EU it is E261, and Codex lists it as an acidity regulator and preservative.
As a buffer it helps keep a seasoning at a steady acidity, working alongside acetic acid in the blend. On SeekSnack it is listed with acetic acid (INS 260), calcium lactate and a sodium phosphate as the acidity regulators of Lay’s Rock Ridged Seafood Cheese Pizza, while the other Lay’s pizza flavours use sodium acetate in its place.
