To test a utensil not labeled for microwave use, put 1 cup of tap water in a glass measure. Place the water in the microwave oven along with (but not touching) the utensil to be tested; microwave on high 1 minute. If the utensil feels warm or hot, it is not microwave-safe because it contains metal in the material or glaze. Do not use it. The utensil and/or the bottom of the oven might crack.

Piece Size : In both conventional and microwave cook-ing, small pieces cook faster than large ones. Pieces which are similar in size and shape cook more evenly.

Starting Temperature : Foods taken from the refrigera¬tor take longer to cook than foods at room temperature. Timings in our recipes are based on the temperatures at which you normally store the foods.

Density of Food : In both conventional and microwave cooking, dense foods, such as a potato, take longer to cook or heat than light, porous foods, such as a piece of cake, bread or a roll.

Quantity of Food : In both types of cooking, small amounts usually take less time than large ones. This is most apparent in microwave cooking, where time is di-rectly related to the number of servings.

Shape of Food : In both types of cooking, thin areas cook faster than thick ones. This can be controlled in micro-waving by placing thick pieces to the outside edge with thin pieces to the center.

Height in Oven : In both types of cooking, areas which are closest to the source of heat or energy cook faster. For even microwaving, turn over or shield vulnerable foods which are higher than 5 inches.

Boiling : Microwaves exaggerate boiling in milk-based foods. A temperature probe turns off the oven before foods boil over. Use a lower power setting and watch carefully when not using a probe.

Prick Foods to Release Pressure : Steam builds up pressure in foods which are tightly covered by a skin or membrane. Prick potatoes (as you do conventionally), egg yolks and chicken livers to prevent bursting.

Round Shapes : Since microwaves penetrate foods to about 1 -in. from top, bottom and sides, round shapes and rings cook more evenly. Corners receive more energy and may overcook. This may also happen con¬ventionally.

Bury Vulnerable Foods : Foods which attract microwave energy, such as cheese or meat, should, when possible, be buried in sauce or other ingredients. In conventional stewing or pot roasting, meat not covered with liquid dries out.

Freshen Snacks, chips, pretzels, etc. by microwaving them, uncovered, for a few seconds. Let stand a minute or two to crisp. Dry a quart of bread crumbs or croutons at High 6 to 8 minutes, stirring every 2 minutes.

Paper Napkin or towel will absorb excess moisture. Dry herbs between 2 layers of towel or napkin until they can be crumbled. Line a cake dish with a paper towel to ab¬sorb moisture during cooking and make cake easy to turn out of the dish.

Sprinkle a little fruit juice or water over dried fruits, cover with plastic wrap and microwave 1/2 to 1 minute at High to moisten and plump them.

Wet Paper Towel, with excess water squeezed out, provides enough moisture to steam fish fillets and scallops. Wrap tortillas or crepes in damp towel and microwave at High 1/2 minute or more to soften them.

Add Water or sauce when reheating dry leftovers. A tablespoon of water or sauce is sufficient, and will not change the flavor of food or cause overcooking. Moisture creates steam for even reheating.

Soften lumpy brown sugar by placing in a microwave oven proof container with a slice of apple. Cover or seal tightly and microwave 1/4 minute or more, until moisture from the apple has softened the sugar.

Porous Cover : Such as paper towel or napkin, allows steam to escape while it promotes even heating and prevents spatters. Use to cover bacon, sandwiches and some vegetable custards.

Light Cover : Of wax paper holds in heat for faster cooking without steaming food. It is frequently used to cover some fruits and meats, such as chicken, hamburgers or roasts, which do not need steam to tenderize them.

Tight Cover : Of plastic wrap holds in steam as well as heat. Turning back one edge as a vent allows excess steam to escape, so wrap will not split during cooking. Vegetables and fish should be steamed.

Utensil Cover : Can be used instead of plastic wrap when you are microwaving vegetables, saucy casseroles and meats which require moisture and steam to tenderize them.

Cooking Bags : Also hold in steam. If the bag has a foil strip on the end, remove it. Cut a 1/2-in. wide strip from the open end of the bag to serve as a tie. Do not use metal twist ties. Make an X-shaped slash to vent.

Freezer Bags : hold moisture in foods and serve as both cooking utensil and cover. Pierce the top of the bag with a knife to vent. Package leftovers in single portions for easy-to-heat homemade frozen entrees.

Rick potatoes in several places to low steam to escape.

Arrange potatoes in a ring so that all sides can be exposed to equal amounts of microwave energy.

Turn Over and rearrange potatoes half way through cooking.

Repositioning a dish in the oven helps food cook evenly. To rotate 1/2 turn, turn the dish until the side which was to the back of the oven is to the front. To rotate 1/4 turn, turn the dish until the side which was to the back of the oven is to the side.

When microwaving, arrange foods with the thickest portions to the outside of the dish. This enables them to cook through without overcooking the thinner areas. Arrange foods of equal size in a ring, leav¬ng the center empty.

In both conventional and microwave cooking, covers hold in moisture and speed heating. Conventionally, partial covering allows excess steam to escape. Venting plastic wrap or covering with wax paper serves the same purpose when microwaving.

In a conventional oven you shield turkey oreasts or baked foods to prevent over-browning. When microwave defrosting, you use small strips of foil to shield thin parts, such as the tips of wings and legs on poultry, which would cook before larger parts were de¬frosted.