Bating (leather)

This step was followed by drenching, a term denoting skins that were thoroughly washed in a bath solution of bran (usually of barley or rye), or ash bark.

[4] One of the early inventions made to replicate bating was the chemical use of old lime liquors (with high levels of ammonia) neutralized with sulphuric acid.

[5] Puering fell into disuse after Robert Hasenclever [de] began producing the enzyme pancreatin on an industrial scale between 1895 and 1897.

[10] Enzymatic soaking of the raw hides has been shown to loosen the scud, initiate the opening of the fibre structure, and to render a leather product with less wrinkled grain when used at an alkaline pH of less than 10.5.

[12] One of the earliest references to puering is found in the old rabbinic Minor tractate, Kallah Rabbati (end of chapter 7): "What is the reason that dogs were privileged to have books of the Law and doorpost scripts prepared from their excrement?

A record of primitive tanning bequeathed in the 12th century by Abraham ben Isaac of Narbonne (1085–1158) mentions the tanning method employed in his day, in southern France, where the treatment of the rawhide by puering was still in use and done after the hairs of the animal were removed by lime in preparation for writing a Torah scroll and the hide had once again become stiff: After taking dry [sheep]-skins whose wool had been soaked [in lime water for removal], they leave them in the water for the duration of time needed for them to become soft [=soaking].

[13]Tanners in Egypt in the 12th century and in Yemen of late made use of different methods in varying degrees, yet without the use of puering and bating, and without the use of gallnuts.