The many varieties of prepared mustards have a wide range of strengths and flavors, depending on the variety of mustard seed and the preparation method. The basic taste and "heat" of the mustard are determined largely by seed type, preparation and ingredients.[19][20] Preparations from the white mustard plant (Sinapis alba) have a less pungent flavor than preparations of black mustard (Brassica nigra) or brown Indian mustard (Brassica juncea). The temperature of the water and concentration of acids such as vinegar also determine the strength of a prepared mustard; hotter liquids and stronger acids denature the enzymes that make the strength-producing compounds. Thus, "hot" mustard is made with cold water, whereas using hot water produces a milder condiment, all else being equal.