Annatto, also known as achiote, is both a flavoring and a colorant. It is the seed of a bush, Bixa orellana, native to tropical America, and is much used in various cooked dishes from southern Mexico to northern South America. The bright red-orange pigment bixin is found in the waxy coating of the seeds, and readily changes into a number of chemical variants that are different shades of orange, yellow, and red. Some of these are soluble in water, others in oil; large food manufacturers use annatto extracts to give a vivid color to cheddar-style cheeses, butter, and other products. Annatto seeds are hard, and difficult to grind finely, so they’re often heated in a liquid to extract their flavor and color and then are strained out. Commercially ground annatto pastes are also available. The aroma of annatto is dominated by the woody, dry terpene humulone, which is also found in hops.