On average, whole milk has 3.5 percent butterfat, low-fat milk either 1 or 2 percent, and nonfat or skim milk, less than .5 percent. Heavy cream has a minimum butterfat of 36 percent, while half-and-half must have between 10.5 and 18 percent butterfat.

Milk is usually homogenized, meaning it’s forced through tiny openings under pressure, which breaks apart the fat globules and disperses them evenly through the milk so they don’t rise as cream to the top. Pasteurization heats milk to inhibit bacteria, while ultra-pasteurization completely sterilizes milk.

WHAT TO LOOK FOR

Look for milk labeled “organic.” That assures you that the milk is not from cows given bovine growth hormone or routine antibiotics. It’s up to you whether you want whole milk, low-fat milk, or nonfat milk.

You may notice the letters UHT on a milk carton. The letters stand for ultra-high-temperature pas-teruization (the same thing as ultra-pasteurization), in which the milk is sterilized so it can be stored at room temperature for extended periods and shipped around the country without worrying about spoilage. Although practitioners of ultra-high-temperature processing contend that heating milk to 230°F for several seconds doesn’t alter the milk in any way, the issue remains open. Enzymes, for one thing, don’t survive those temperatures.

Though I have not found them in markets as yet, organic powdered milk, condensed milk (sweetened to 40 percent sugar), and evaporated milk (unsweetened) may some day be offered.

USES

We use organic nonfat milk around my house, but I’ve found that it has different cooking qualities than milk with more fat, and especially cream. The more fat, the less likely the milk or cream is to curdle at high heat. This is true of organic as well as conventional—or even evaporated—milk.

Nondairy milks can be made from nuts and seeds. Whiz almonds, hazelnuts, Brazil nuts, or other nuts or seeds in the blender until powdered, then whiz with water and strain through a cheesecloth-lined colander. Don’t use these milks to cook at high heat, or they will separate. Use them, for instance, on your morning granola.

J. I. Rodale used to say that cows’ milk was made to raise calves, not kids. For kids, he said, the ideal is mother’s milk. Next to that, goat’s milk has a smaller and much more easily digested curd than cows’ milk, and it is much gentler to a baby’s young digestive system than cows’ milk. For those who are lactose intolerant, organic soy and rice milks are widely available. I have not cooked with them, but I have made ice cream from rice milk and it tasted sweet, pure, and good.  ....read more