Curry powder is a blend of spices which is designed to be used in Indian cooking. In India, cooks prefer to prepare their spices freshly, as needed, ensuring maximum flavor. So, a blend of spices, ground into powder, used to make a curry or a sauce, is called curry powder. Depending on the sauce, the composition of the curry powder changes. Indian cuisine is famous for featuring a wide array of spices, which varies by dish, region, and personal taste.
When British colonists arrived in India, they were captivated by traditional Indian cuisine, particularly the flavorful kari, or “sauces” of Southern India. In a desire to bring some of India back with them, colonists started creating their own curry powder blends, adjusting them for Western tastes and often including turmeric for a distinctive yellow color. So, curry powder is not turmeric singled out, but a mix of spices and turmeric almost always forms a part of this mix for color and its health properties.
In India, such spice blends are known as masalas, and there are hundreds of them to choose from when cooking. The ingredients in a masala are ideally freshly ground and customized to the food being prepared, the occasion, and the time of year, and these spice blends are kept for no more than a month or so to ensure that the flavor stays fresh. Spices used in masalas can include things like: cardamom, nutmeg, mace, mustard seed, pepper, chilies, cinnamon, cloves, coriander, turmeric, cumin, fenugreek, and numerous other spices.