FoodNet

Elements of the theory and practice of cookery

1901

Page 74

Presented as published in 1901. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
B. Put one piece of the bone in diluted hydrochloric acid (six parts of water to one part of acid) ; after a few days compare it with the other piece. Has the acid changed the shape of the bone? Its size? How has it affected it? See if you can tie it in a knot. What makes bone hard? What, then, has the acid taken out of the bone? C. Tie a wire around the other piece of bone, and lay it for half an hour in a hot coal-fire. Remove it by means of the wire. How has it been changed? Does it break easily? What part of the bone has been burned? 283. Structure and composition of bone. — Bone is the hardest of animal tissues, yet it is one-half Avater; the other half consists of about two-thirds mineral, and one- third animal matter, the mineral being largely calcium phosphate, commonly called phosphate of lime; the animal matter chiefly fat and collagen^. In the centre of hollow bone is a mass of fatty stuff, the mar- row. Surrounding, and, in some cases, forming the end of the bone is the flexible, slippery substance called cartilage, or gristle; and, connecting bones at the joints, 1 Often called ossein in bones. 158 THEORY AND PRACTICE OF COOKERY are bands or ligaments of cartilage. Cartilage may be considered soft bone, since it differs from bone mainly in having less mineral matter. The bones of children and young animals are soft because cartilaginous; the older the individual grows, the harder the bones become. The two kinds of material in bone may be separated by soaking in acid, which dissolves the inorganic substance; or by burning, which destroys the organic. 284. How cooking affects bones. — By long cooking in water the insoluble collagen and other gelatinoids of connective tissue, tendon, cartilage, and bone are changed to gelatin, soluble in hot water. ^ But will hot water best draw out the meat juice? How may we contrive to extract all possible food value from both meat and bone ? And how may we also give to soup that rich flavor produced only by heating meat to above 212° F.? All these points must be considered if we mean to make the best possible soup out of our materials. 285. The soup-kettle or stock-pot. — Have for stock- making a deep kettle with a tight-fitting cover; the tighter the cover the smaller is the amount of water lost by evaporation. In an ordinary kettle, stock may, during cooking, lessen by one-half; in a soup-digester with a steam-tight, valved cover, evaporation is so slight that one pint of water instead of one quart may be allowed to one pound of meat and bone. 1 The change from collagen to gelatin, like that from raw starch to starch-paste, is a process of hydration, i.e. of combination with water. THE FLESH OF ANIMALS 159 Fresh material may be added to that already in the stock-pot, provided that once a week the contents are removed and the pot cleaned. Fresh material must be combined with "left-overs" for a satisfactory stock, cooked meat alone yielding too little soluble material. Fresh herbs and, unless a varied stock of cooked vege- tables is on hand, a few fresh vegetables are required for flavoring.