The Scientific Basis of Cookery.

Te Aroha News, Volume I, Issue 40, 8 March 1884, Page 5

The Scientific Basis of Cookery.

The "Times" reports that Mr Mattieu Williams, F.C.S., gave a lecture at the house of the Society of Arts, on "The Scientific Basis of Cookery." The lecturer began by denning the distinction between technical and technological education, the first, properly so called, being the education received by the apprentice in the workshop, the latter that which may be taught to the student in a school or college. Technology, including the philosophy or scientific principles which were technically applied in the practical handicraft. These lectures only attempted the technology; technical teaching must be conducted in the kitchen or such practical establishments as the School of Cookery at South Kensington. He then described the wide rangeof domestic technology, and showed how it exceeded that of ordinary trades and professions. Most of these were confined to one particular class of articles or operations. The housewife had to deal with all our ordinary everyday requirements. She was truly a " universal provider," and a corresponding breadth of technology was demanded. The technology of cookery included organic chemistry, the most obscure and difficult part of the science. All the operations of cookery were chemical operations, and therefore the kitchen was a chemical laboratory, in which the agency of heat was operating to effect certain chemical changes on the organic materials of food. The simple operation of boiling water was explained, and the common domestic fallacy shown up of supposing that simmering water is of lower temperature than water which is boiling rapidly. The temperature of 212', it

was shown, was reached immediately bubbles of steam were formed at the bottom of the vessel and these bubbles rose through the water to the top. As nearly a thousand degrees of heat we c demanded to do the work of converting water into vapour, and as the degrees in excess disappeared altogether as temperature, or were rendered u latent," the keeping up of ebullition was very wasteful. In the so-called boiling of meat, the boiling point was not required, the cooking temperature being about 1(50 degrees— that at which albumen coagulated and became a tender solid. At 212 degrees and above, it became tough and leathery. The cooking of an egg in hot water was described in detail as a typical example showing that, in order to obtain the maximum of tenderness, digestibility, and nutrient value, the egg should not be raised to the boiling point at all, but kept well below it at about ICO degrees to 180 degrees. The principals involved in boiling a leg of mutton were similarly described. At first it should be immersed in water at the full boiling point in order to form an outer coating on well coagulated albumen which shall retain the juices of the meat. After this no more boiling should take place, but a gentle temperature be maintained until it has penetrated to the centre. If meat conducted heat, as many metals did, this would occupy but a lew minutes ; the long time demanded was due to its bad conduction, and the skill of the cook was displayed by overcoming this difficulty in such wise that the degree of cooking should be nearly uniform throughout. Frying, properly conducted, Mr Williams said, was an operation of the same nature as boiling, the heating medium being one that could bo raised considerably higher, the surface of the meat or vegetable being partially decomposed or charred, converted into a caramel or " browned," while the interior was raised to the cooking point of 180 degrees or thereabouts. It could not, therefore, bo applied to large masses, only to comparatively thin pieces. The evils of the popular frying-pan and the necessity for a completo bath ot fat were explained, and a proper frying-pot was exhibited. The fat of the bath, the lecturer pointed out, did not penetrate the meat, provided the meat was fully immersed and the fat was kept well above the boiling point of water, as in this case the steam formed botvveen the flesh fibres prevented its entry ; but if the frying was done on a merely greased plate, like a common frying-pan, the fat was apt to penetrate by the upper surface, which was exposed. Thus, a sole cooked by complete immersion in heated fat absorbed less grease than one which was fried in a modicum of fat just covering the surface ot a frying-pan.