Cream of tartare is potassium hydrogen tartrate used as a stabilising and raising agent in food, essentially the same salt as cream of tartar under a variant name. It provides the acid that reacts with sodium bicarbonate in baking powders and self-raising formulations, releasing the carbon dioxide that leavens cakes and biscuits. In egg-white foams it strengthens the protein network for glossier, more stable meringues. The tartare spelling reflects older usage; modern labels say cream of tartar. Its winemaking origin, tartar crystallising in fermenting wine, connects the bakery to the vineyard through chemistry.