. Very hard, (like parmesan) contain 30 percent water or less. They are bacterial aged.

Because of the relatively small amount of moisture, these cheeses remain stable at

room temperature. For longer shelflife, it is still best to refrigerate them.

Processed cheese

One cheese is in a category of all its own—pasteurized processed cheese, a truly

American invention that enjoys great popularity because of its unobtrusive, almost bland flavor,

great versatility, long shelflife and low price. Processed cheese is a combination of several

cheeses in which the processor blends cream, water, salt, emulsifier and coloring. The next

processing step is to grind up and blend the cheese, then pasteurize and package it. Thanks to

pasteurization, this cheese has a very long shelflife (measured in months) and stable flavor.

In the 1990s cheese processors have developed new processed cheeses that are in an

entirely different, higher class. Made from a combination of good-quality, flavorful cheeses, they

have a very respectable taste, and only the smooth, slightly soft texture and its label give them

away as processed cheeses.

Here is a final note on a special kind of processed cheese, called filled cheese (or cheese

analogue). The food processing industry uses a great deal of it because it is inexpensive, has

extra-long shelflife and still has cheese flavor. In filled cheese they replace the original milk fat

with lower-priced vegetable oils or other fats, otherwise processing follows the usual cheese

making steps. The manufacturers of packaged foods use most filled cheese in lower-priced

cheese-like foods, on prepared sandwiches, in frozen pizzas, in cheese sauces and as extenders of

more costly natural cheeses in the food service industry. They have poor flavor compared to

natural cheeses, even processed cheeses, but their keeping quality is excellent. They also have

less cholesterol and calories than real cheese. It is not for cheese-lovers but for people on low

food budgets.

How Dairy Performs in the Kitchen

All of the 60-odd proteins in milk fall into two categories. In one group they precipitate

either in acid or on heat, and in the other they remain in solution. This is an important distinction

in the kitchen that asks for some clarification.

Milk and acid

In its natural state, milk is very slightly acid (pH 6.5). One protein, casein, which makes

up 80 percent of all milk proteins, precipitates in mild acid conditions but natural acidity is not

acid enough. When milk starts getting old, bacteria produce lactic acid, the milk becomes mildly

acidic (turns sour), and casein precipitates as curds. If you let the milk sit longer, with more

lactic acid it becomes more acidic, and another group, whey proteins, also precipitate, and even

more curds develop.

If you add anything quite sour like citrus juice, vinegar or tart fruits, the milk curdles

instantly as the casein precipitates. Sometimes we do this deliberately, making custards with fruit

juices or fruits, for example, but the soft curds will disperse when slowly heated in the oven, and

add firmness to the custard. Most of the time, you don’t want milk to curdle. To prevent this, mix

starch (in the form of flour, cornstarch, tapioca) with the acid ingredient. Starch keeps the casein

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