Anatomy of milk
• Raw cow's milk is about 87 percent water, about 5 percent sugar, about 3 1⁄2 percent protein, and just under 4 percent fat.
• Because fat is lighter than water, unhomogenized milk separates so that cream rises to the top; when skimmed off, the milk that's left is almost fat-free.
• One cup of milk contains about 102 milligrams of sodium.
• Ninety-eight percent of milk in the United States is vitamin D-fortified; one cup of fortified milk contains 25 percent of the Daily Value for vitamin D.
• When fat is removed from milk, vitamin A is removed, too. That's why two percent, one percent, and fat-free milk are most often fortified with this vitamin. One cup of fortified milk contains 10 percent of the Daily Value for vitamin A.
• One cup of milk also provides 20 percent of the Daily Value for phosphorous.
With none of its inherent fat removed, whole milk is thick and rich. Each eight-ounce glass has 146 calories, 7.9 grams of fat, and 276 milligrams of calcium. Whole milk is recommended as a beverage for children under the age of two, but in most cases is considered too high in fat for adults and older children to drink regularly. It can, however, play an important role in cooking. It adds silky texture to sauces and soups, contributes flavor and texture to baked goods, and lends golden gloss to doughs and crusts.
An eight-ounce glass of two percent (reduced-fat) milk contains 121 calories, 4.7 grams of fat, and 297 milligrams of calcium, while the same serving of one percent, or low-fat, milk has 102 calories, 2.6 grams of fat, and 300 milligrams of calcium. How do you know which one to use?
When considering which milk to drink, the question is simply how much you value the increased creaminess of the two percent milk over the reduction in calories and fat of one percent or fat-free milk. When cooking, the decision is often more clear. For example, when making ice cream, you may need more fat for better results. The fat in the milk not only lends fullness of flavor but also interferes with the formation of ice crystals so the ice cream is rendered velvety smooth.
Other dishes, like the flour-thickened sauce in Stovetop Mac and Cheese, rely on other ingredients or techniques for texture and are dependent on milk mostly for flavor and liquidity. So a lower-fat milk works fine in these cases.
Fat-free milk is many people's milk beverage of choice. Also called skim milk, it contains no fat, only 83 calories, and 306 milligrams of calcium per eight-ounce glass. Lower-fat milks have more calcium per cup than whole milk because in whole milk some of the volume is displaced by milk fat, which has no calcium. Use fat-free milk on cereal, in coffee, as a drink-and to make certain dishes, such as puddings and cheese sauces, where the milk provides background flavor, and other ingredients, such as flour or cornstarch, lend texture.
Whipping cream (or heavy whipping cream) has 51 calories and 5.6 grams of fat per tablespoon. When beaten, whipping cream doubles in volume to create a classic dessert topping. (Neither light whipping cream nor light cream contains enough fat to hold its shape when whipped.) Whipping cream is the only type of milk that is heat stable-that is, it won't curdle when brought to a boil. Use it to enrich sauces and soups, adding just a bit at a time-it can take as little as a tablespoon to add the right amount of body and rich mouthfeel.
Half-and-half is a mixture of equal parts milk and cream, and weighs in with only 20 calories and 1.7 grams of fat per tablespoon. Use it to finish sauces and soups, but add it off the stove or over lower heat to prevent it from curdling.
Buttermilk was traditionally the liquid that remained after butter was churned from cream. Today, buttermilk is made by adding bacteria cultures to fat-free, low-fat, or whole milk. Buttermilk has a thick consistency and tart flavor. It's often used for cakes, biscuits, pancakes, and quick breads.
Acidophilus milk is whole, reduced-fat, or fat-free milk with friendly Lactobacillus acidophilus bacteria added to it. The bacteria is believed to benefit the digestive tract, much the same way yogurt does.