The Chemistry of Cookery

I have lately tasted samples of pure ‘bosch’ or ‘oleomargarine’ undistinguishable from churned cream or good butter, though offered for sale at 8½_d._ per lb. in wholesale packages. In the preparation of this the high temperatures of the process of the Academicians are carefully avoided, and the smoothness of pure butter is obtained. I mention this now merely in confirmation of my theory of the _rationale_ of fat cookery, but shall return to this subject of ‘bosch’ or butterine again, as it has considerable intrinsic interest in reference to our food supplies, and should be better understood than it is. If this theory of fat cookery and the preceding theoretical explanations of the cookery of gelatin and fibrin are correct, a broad practical deduction follows, viz. that in the cookery of fat the full temperature of 212° or even a much higher temperature does no mischief, or may be desirable, while all the other constituents of meat are better cooked at a temperature not exceeding 212°; the albumen especially at a considerably lower temperature. There is neither coagulation nor dehydration to be feared as regards the fat, unless the heat is raised to that of the dissociation of the fixed oils, which, as already explained, is much above 212°; the change which then takes place in the fat (analogous to that caramelising sugar) is not dehydration properly so called, although the _elements_ of water or hydrogen may be driven off. Hydration is a combining of water _as water_, not with the elements of water as elements, and the water of most hydrates becomes dissociated at a temperature a little above the boiling point of water. My own experiments on gelatin show that hydration occurs when crude gelatin is exposed to the action of water at or below the boiling point, and that dehydration takes place at and above the boiling point, or otherwise stated, the boiling point is the critical temperature where either hydration or dehydration may occur according to the circumstances. The original membrane _immersed in water_ at 212° becomes hydrated, while hydrated gelatin heated to 212° and exposed