Culinary Chemistry / The Scientific Principles of Cookery, with Concise Instructions for Preparing Good and Wholesome Pickles, Vinegar, Conserves, Fruit Jellies, Marmalades, and Various Other Alimentary Substances Employed in Domestic Economy, with Observations on the Chemical Constitution and Nutritive Qualities of Different Kinds of Food.

by Friedrich Christian Accum

One of the most essential conditions to be attended to in the boiling of meat is, to skim the pot well, and keep it really boiling, the slower the better. If the skimming be neglected, the coagulated albuminous matter will attach itself to the meat, and spoil the good appearance of it.

It is not necessary to wrap meat or poultry in a cloth, if the pot be carefully skimmed. The general rule of the best cooks is to allow from 20 to 30 minutes slow simmering to a pound of meat, reckoning from the time the pot begins to boil.

The cover of the boiling pot should fit close, to prevent the unnecessary evaporation of the water, and the smoke insinuating itself under the edge of the cover, and communicating to the boiled substance a smoky taste.

Cooks often put a trevet, or plate, on the bottom of the boiling pot, to prevent the boiled substance sticking to the pot.

Rationale.—When flesh or fish is boiled in an open vessel, or one not closely covered, the fibrous texture is rendered more tender: at the same time its nutritive quality is not much diminished. For the temperature of the water or steam, never exceeding 212°, is insufficient to produce the partial charring, which roasting and broiling effect. But, as in stewing, the gelatine, albumen, osmazome, and fat, are developed and disengaged, and becoming united with the liquid in the vessel, form a soup, or broth. The paler colour of boiled meat is owing to the blood being separated and diffused in the water. In frying, the boiling fat or oil enters into the interstices of the fibres, which the disengaged animal juices have left empty. In boiling, in a similar way, the hot water takes the place of the blood, gelatine, fat, and albumen, which have been dissolved and separated from the fibres. The fibres are in this manner soaked and washed, first by the boiling water, and afterwards by the soup or broth which is formed, till the whole texture assume a softened consistence, and pale appearance. It is this, rather than any softening of the fibres themselves, which seems to be the real effect produced, unless, with some, we consider the fibres as nothing more than minute and close-set bundles of blood vessels. This doctrine, however, the experience of every cook will disprove; for if the boiling be long continued, the fibres of the meat will alone remain, and so far from becoming more soft and pulpy, they will become dry and juiceless. If indeed the boiling point of the water be artificially increased above 212°, by pressure applied to the surface of the liquid, the fibres may be reduced to a pulp, quite homogeneous. When this is done by Papin’s digester, or by any other apparatus of the same kind, and when the process under such circumstances is long continued, the hardest bones may be converted into jelly.

It is only by boiling that the more gelatinous parts of flesh can be completely extracted unaltered from such parts as are cartilaginous, ligamentous, or tendinous.

COMPARISON OF THE CHEMICAL CHANGES PRODUCED ON ANIMAL AND VEGETABLE FOOD, IN THE DIFFERENT PROCESSES OF COOKERY.

The principal operations of cookery which we have just examined and explained, all agree in this, that they effect some chemical change on the materials operated upon, by which they are rendered more digestible, more wholesome, and consequently more nutritive.

In such of the operations as are performed by the direct application of heat to the flesh of animals, namely, roasting, baking, frying, and broiling, the meat loses the vapid and nauseous taste and odour which it possesses in a raw state, and becomes savoury, juicy, and grateful to the taste. These effects arise from the development of the gelatine and osmazome from the smaller vessels, and their being rendered soluble; while, at the same time a portion of the fat is liquified, and combines with them after they are disengaged.

The fibres again, on the surface of the meat, are partly scorched, and form a crust, which, except in the interstices of the corrugations, is impermeable, and consequently prevents the savoury gravy that is disengaged from the fibres from oozing out or becoming evaporated. It is thus only disengaged from its chemical union with the fibres, and remains mechanically united with them in the meat, after it is cooked, as we see upon cutting into the fibrous portion.