Cream is a dairy product composed of the higher-butterfat layer skimmed from the top of milk before homogenization. In un-homogenized milk, the fat, which is less dense, will eventually rise to the top. In the industrial production of cream, this process is accelerated by using centrifuges called "separators". In many countries, cream is sold in several grades depending on the total butterfat content. Cream can be dried to a powder for shipment to distant markets. Cream has high levels of saturated fat. Cream skimmed from milk may be called "sweet cream" to distinguish it from whey cream skimmed from whey, a by-product of cheese-making. Whey cream has a lower fat content and tastes more salty, tangy and "cheesy".[3] In many countries, cream is usually sold partially fermented: sour cream, crème fraîche, and so on. Cream has many culinary uses in sweet, bitter, salty and tangy dishes. Cream produced by cattle (particularly Jersey cattle) grazing on natural pasture often contains some natural carotenoid pigments derived from the plants they eat; this gives the cream a slight yellow tone, hence the name of the yellowish-white color, cream. This is also the origin of butter's yellow color. Cream from goat's milk, or from cows fed indoors on grain or grain-based pellets, is white.