N. Upon standing, unhomogenized milk naturally separates into two layers — a milk fat-rich cream on top and almost fat-free (or skimmed) milk on the bottom. Commercially, the cream is separated from the milk by centrifugal force. Almost all cream that reaches the market today has been pasteurized. There are many varieties of cream, all categorized according to the amount of milk fat in the mixture. Light cream, also called coffee or table cream, can contain anywhere from 18 to 30 percent fat, but commonly contains 20 percent. Light whipping cream, the form most commonly available, contains 30 to 36 percent milk fat and sometimes stabilizers and emulsifiers. Heavy cream, also called heavy whipping cream, is whipping cream with a milk fat content of between 36 and 40 percent. It's usually only available in specialty or gourmet markets. Whipping cream will double in volume when whipped. Half-and-half is a mixture of equal parts milk and cream, and is 10 to 12 percent milk fat. Neither half-and-half nor light cream can be whipped. Ultrapasteurized cream, seen more and more in markets today, has been briefly heated at temperatures up to 300°F to kill microorganisms that cause milk products to sour. It has a longer shelf life than regular cream, but it doesn't whip as well and it has a slight "cooked" flavor. All other cream is highly perishable and should be kept in the coldest part of the refrigerator. Pressurized whipped cream, contained in cans under pressure, is a mixture of cream, sugar, stabilizers, emulsifiers and gas, such as nitrous oxide. It's not really "whipped" but, more aptly, expanded by the gas into a puffy form. Aerosol "dessert toppings," which are usually made with hydrogenated vegetable oils, have absolutely no cream in them . . . and taste like it. Read the label — the fat content of real cream mixtures must be indicated on the product label. See also clotted cream; crème fraîche; sour cream. cream v. To beat an ingredient or combination of ingredients until the mixture is soft, smooth and "creamy. " Often a recipe calls for creaming a fat, such as butter, or creaming a mixture of butter and sugar. When creaming two or more ingredients together, the result should be a smooth, homogeneous mixture that shows neither separation nor evidence of any particles (such as sugar). Electric mixers and food processors make quick work of what used to be a laborious, time-consuming process.