WHAT HAPPENS IN COOKING PHYSICAL CHANGES

Wonderful things happen in cooking, and we do not yet know all of them, or the reasons for them-though the reasons for physical changes are better understood than those for chemical changes. Nearly every thing loses weight in cooking. Meat, even when it is boiled in water, loses weight from its shrinkage through heat, which squeezes out much of its water content. Melting of the fat, too, results in loss of weight. More weight in proportion is lost in cooking a small piece of meat than in cooking a large piece, but an allowance of 25% loss in weight is a fair average.

Bread and cakes swell, but though they increase in volume, they lose in weight through evaporation of water. It requires two extra ounces of dough to produce a one-pound loaf of bread. Cereals, also macaroni and other Italian pastes, increase greatly in both weight and volume, through absorption of water. So do dried vegetables and fruits. Though other physical changes occur, those in weight and volume are the most important in cooking.

CHEMICAL CHANGES

The change in color of red meat to gray is one of the physical changes that indicate a chemical change. Heat causes a breaking up of the chemical substance to which meat owes its red tint. The brown crust on the loaf, or on the outside of the cake or pie, means that starch has been changed to dextrin, and sugar caramelized.

In boiling fruit and sugar together, as in making cranberry or apple sauce, a chemical change is brought about in the sugar, which is transformed into another kind of sugar not so sweet as the granulated cane that was originally used. This new sugar is only three-fifths as sweet. Here then is a hint for economy of sugar, by cooking the fruit sauce without sugar, and adding sugar when the fruit is done. In this last way, theoretically, three pounds of sugar will sweeten as much as five pounds that were cooked in with the fruit-provided it was cooked long enough to change it completely into the form of glucose that is only three-fifths as sweet as cane. In any case there will be considerable saving of sugar when it is added last.

Many other important and interesting chemical changes occur in cooking, but a review of them here would not add a great deal of practical value in everyday use of the range.

The foregoing hints are confined largely to the mechanical operation and care of the range. So much depends on the preparation of foods for cooking that the temptation to add several pages of palatable recipes is very strong.- Recipes are easily obtained, however, and the real purpose of this booklet is to suggest ways of getting consistently better results with the range and draft as they are. If the range "works well" all the time, both the stove and the draft are all right. If the range has "off days," the chimney draft needs attention. A cleaning out may help or perhaps an extension of the chimney to a point where the air currents will improve the draft.

If you are getting good results only part of the time, you should get much better results the rest of the time, by making a study of the conditions of fire and draft, when the stove is at its best. If the range fails to give satisfaction the greater part of the time, look for serious defects in the range itself or in the conditions of its installation or operation. No range could do satisfactory work any of the time if it had serious defects. If it is racked or broken or worn out, it is past its usefulness. Its operation becomes rapidly more wasteful and irritating and the early installation of a new range will be good economy and good sense.

• This may become the subject of a separate volume and we would be glad of any suggestions. If you have a favorite recipe, especially one that has not been published, we would be glad to have you contribute it for this book. The Portland Stove Foundry Co., Portland, Maine.