TALLOW (M.E. talugh, talg, cf. Du. talk, L. Ger. talg ; the connexion with O.E. taelg, dye, or Goth, tulgus, firm, is doubtful), the solid oil or fat of ruminant animals, but commercially obtained almost exclusively from oxen and sheep. The various methods by which tallow and other animal fats are separated and purified are dealt with in the article OILS. Ox tallow occurs at ordinary temperatures as a solid hard fat having a yellowish white colour. The fat is insoluble in cold alcohol, but it dissolves in boiling alcohol, in chloroform, ether and the essential oils. The hardness of tallow and its melting-point are to some extent affected by the food, age, state of health, etc., of the animal yielding it, the firmest ox tallow being obtained in certain provinces of Russia, where for a great part of the year the oxen are fed on hay. New tallow melts at from 42-5 to 43 C., old tallow at 43-5, and the melted fat remains liquid till its temperature falls to 33 or 34 C. Tallow consists of a mixture of two-thirds of the solid fats palmitin and stearin, with one-third of the liquid fat olein.
Mutton tallow differs in several respects from that obtained from oxen. It is whiter in colour and harder, and contains only about 30 per cent, of olein. Newly rendered it has little taste or smell, but on exposure it quickly becomes rancid. Sweet mutton tallow melts at 46 and solidifies at 36 C.; when old it does not melt under 49, and becomes solid on reaching 44 or 45 C. It is sparingly soluble in cold ether and in boiling alcohol.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)