Greg Brinkman, age 12, of Tulsa, Okla., for his question:

HOW DOES A PRESSURE COOKER WORK?

A food pressure cooker is actually a steamer. A small amount of water is put into the cooker along with the food, and the steam that develops in the sealed chamber actually does the cooking.

Steam under pressure usually cooks the food very quickly. The pressure is registered on a gauge on top of the cooker. There is a temperature rise in the cooker with increasing pressure.

Pressure cookers may be purchased in various sizes, ranging from about two quarts to 20 quarts. The larger size pots usually have racks with sets of pans inside. Several kinds of foods requiring similar cooking times can then be prepared at once.