Bating, a technical term used in the tanning industry to denote leather that has been treated with hen or pigeon manure, similar to puering (see puer) where the leather has been treated with dog excrement, and which treatment, in both cases, was performed on the raw hide prior to tanning in order to render the skins, and the subsequent leather, soft and supple. [1] Today, both practices are obsolete and have been replaced in the tanneries with other natural proteolytic enzymes.
Since early times, tanners have made use of either dog fæces, or hen and pigeon manure, in one of the early phases of leather treatment to produce a soft leather. [2] A bath solution containing the animal extracts was made and the raw hide inserted and left there for a few days, which activated the bacteria and enzymes that reacted with the collagen in the animal skin to make the leather soft and supple. 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. [3] This process was thought to open up the fibre, and, if lime (Ca O) was used to remove hair before the actual bating, drenching removed excess or residual lime trapped in the leather. [3]
Early inventors who concerned themselves with tanning looked upon bating as a process for removing lime from the skins, and nothing more, and since the use of animal fæces was repulsive, sought to substitute them by inventing artificial bates. [4] What they failed to realize, however, was that bating also acts upon the skin fibres, rendering portions of the skins soluble, bringing about the finished condition. [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] This method more nearly approximates to the conditions of the dung. [5]
Puering fell into disuse after Robert Hasenclever began producing the enzyme pancreatin on an industrial scale between 1895 and 1897. By 1907, it was used by Otto Röhm in the tannery. [6] J.T. Wood, investigating the microbial properties of dog fæces, was able to isolate species of different bacteria, determining that aged dog fæces was more potent (hence, more efficacious) than fresh dog fæces. [7] The bacteria that settles on the excrement releases, under right conditions, the principal enzyme trypsin. [7]
Primitive tanning methods differed from country to country, but the use of puering and bating was not prevalent in all of them, as tanners had moved away from their use and employed vegetable tanning which achieved nearly the same result. In western societies, modern tanning techniques tried to replicate the effect of puering and bating by using a natural bate. Papain, the active proteolytic enzyme found in the latex taken from the skin of the papaya fruit (Carica papaya), [8] is thought to replicate the action of traditional puering and bating. The protein-digesting enzyme is now used extensively in the leather industry, and follows the dehairing of the animal skin, usually with lime and other proteolytic enzymes, and the deliming of the animal hide with mineral acid. [9] This process is thought to release traces of lime still trapped in the hide after the deliming process, in addition to removing unwanted grease, besides aiding in the subsequent tanning process by the alteration of protein. [9]
Today, in the modern tanning industry where almost all innovations have been made by substituting vegetable tanning agents with chemical agents, bating is the only step in leather processing where enzymatic process cannot be substituted by chemical processes, as the process of bating gives certain desired characteristics to the finished leather. [10] Large-scale use of microbial enzymes, following the introduction of fermentation technology, has become standard in the tanning industry. [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. [11] In rabbit skins it improves the softness and elasticity, and increases the surface area yield of the fur by 3.3%. [11] Bating also acts to hydrolyze casein, elastin, albumin, globulin-like proteins, and nonstructural proteins that are not essential for leather making. [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? It is because it says [of them]: 'not a dog shall bark against any of the people of Israel' (Exo. 11:7)." 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]. Afterwards, they put them inside a pit made for them, and they put therein a little dog fæces, having no prescribed quantity [=puering], and a little salt [is added thereto], and then they seal the mouth of the pit, leaving it there for one day in summer months, and three days in winter months, no longer [than the duration of that time], so that they be not eaten up. They then remove them and check them for holes, and if there be a hole found, they sew it, and then lay them out over a wooden frame that is prepared in advance [for this purpose] and they rinse them thoroughly with running water [=drenching], and then bring out a heaping batch of gallnuts which they then pound or grind thoroughly. They then put on each sheet of leather three litres of the Baghdad measure, and plaster thereon the gallnuts, over its two sides, and sprinkle a little water over them, and they put more gallnuts on that side of the leather where the hairs once were (grain layer) than what they do on the flesh-side [of the leather], doing likewise with each sheet of leather, the application [of gallnuts] made twice daily, while, on the third application, they once more plaster with what remains of the gallnuts [onto the leather] and lay it out in the sun, for the duration of time that it takes for it to whiten, leaving it in that state until it dries [=tanning]. They afterwards shake-off the excess gallnuts and then cut the leather. [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. Rather, after soaking and fleshing, tanners utilized the tannins found in the ground leaves and crushed tender stems of Acacia (Acacia etbaica and Acacia nilotica kraussiana), [14] [15] [16] [lower-alpha 1] with which a bath solution was made and the raw hides inserted and left there for about two weeks, constantly stirring and changing the water after one week. In some places in Yemen, the leaves of African rue ( Peganum harmala ) were used instead of Acacia leaves. In Yemen and Ethiopia, castor-bean oil derived from the castor plant ( Ricinus communis ) was applied by some tanners to the finished leather product which gave additional softness and suppleness to the leather.
Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hogs, and aquatic animals such as seals and alligators.
Tannins are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
Tanning is the process of treating skins and hides of animals to produce leather. A tannery is the place where the skins are processed.
Tefillin, or phylacteries, are a set of small black leather boxes with leather straps containing scrolls of parchment inscribed with verses from the Torah. Tefillin are worn by adult Jews during weekday morning prayers. In Orthodox and traditional communities, they are worn solely by men, while some Reform and Conservative (Masorti) communities allow them to be worn by any gender. In Jewish Law (halacha), women are exempt from most time-dependent positive commandments, which include tefillin.
Catechu is an extract of acacia trees used variously as a food additive, astringent, tannin, and dye. It is extracted from several species of Acacia, but especially Senegalia catechu, by boiling the wood in water and evaporating the resulting brew. It is also known as cutch, black cutch, cachou, cashoo, terra Japonica, or Japan earth, and also katha in Hindi, kaath in Marathi, khaira in Odia, khoyer in Assamese and Bengali, and kachu in Malay.
Jacob ben Meir, best known as Rabbeinu Tam, was one of the most renowned Ashkenazi Jewish rabbis and leading French Tosafists, a leading halakhic authority in his generation, and a grandson of Rashi. Known as "Rabbeinu", he acquired the Hebrew suffix "Tam" meaning straightforward; it was originally used in the Book of Genesis to describe his biblical namesake, Jacob.
Klaf or Qelaf is the designation given a particular piece of skin. The Talmudic definition includes both the form of the skin and the way it is processed, in particular, that it must be tanned. Since the innovative ruling of Rabbeinu Tam it is primarily used to refer to parchment or vellum. It is one of the materials upon which a sofer writes certain Jewish liturgical and ritual documents.
Gevil or gewil or is a type of parchment made from full-grain animal hide that has been prepared as a writing material in Jewish scribal documents, in particular a Sefer Torah.
A tag is a decoration drawn over some Hebrew letters in the Jewish scrolls of Sifrei Kodesh, Tefillin and Mezuzot. The Hebrew name for this scribal feature is kether (כתר). Tag and kether mean 'crown' in Aramaic and Hebrew respectively.
Tanbark is the bark of certain species of trees, traditionally used for tanning hides into leather.
The leather manufacturing process is divided into three sub-processes: preparatory stages, tanning and crusting. All true leathers will undergo these sub-processes. A further sub-process, surface coating may be added into the sequence. The list of operations that leathers undergo vary with the type of leather.
Ktav Stam is the specific Jewish traditional writing with which holy scrolls, tefillin and mezuzot are written. Stam is a Hebrew acronym denoting these writings, as indicated by the gershayim punctuation mark. One who writes such articles is called a sofer stam. The writing is done by means of a feather and ink onto special parchment called klaf. There exist two primary traditions in respect to the formation of the letters, Ktav HaAshkenazi and Ktav HaSefardi, however the differences between them are slight.
Kil'ayim are the prohibitions in Jewish law which proscribe the planting of certain mixtures of seeds, grafting, the mixing of plants in vineyards, the crossbreeding of animals, the formation of a team in which different kinds of animals work together, and the mixing of wool with linen in garments.
Humanity has used animal hides since the Paleolithic, for clothing as well as mobile shelters such as tipis and wigwams, and household items. Since ancient times, hides have also been used as a writing medium, in the form of parchment.
Leather has played an important role in Judaism and in Jewish life. Many items widely used by observant Jews are made from leather, such as:
Russia leather is a particular form of bark-tanned cow leather. It is distinguished from other types of leather by a processing step that takes place after tanning, where birch oil is worked into the rear face of the leather. This produces a leather that is hard-wearing, flexible and resistant to water. The oil impregnation also deters insect damage. This leather was a major export good from Russia in the 17th and 18th centuries because of its high quality, its usefulness for a range of purposes, and the difficulty of replicating its manufacture elsewhere. It was an important item of trade for the Muscovy Company. In German-speaking countries, this leather was also known by the name Juchten or Juften.
The conservation and restoration of leather objects is the process of determining the causes of deterioration, followed by deciding the best course of action for preserving the leather objects for the future.
Yemenite scrolls of the Law containing the Five Books of Moses represent one of three authoritative scribal traditions for the transmission of the Torah, the other two being the Ashkenazi and Sephardic traditions that slightly differ. While all three traditions purport to follow the Masoretic traditions of Aaron ben Moses ben Asher, slight differences between the three major traditions have developed over the years. Biblical texts proofread by ben Asher survive in two extant codices, the latter said to have only been patterned after texts proofread by Ben Asher. The former work, although more precise, was partially lost following its removal from Aleppo in 1947.
Corpse uncleanness is a state of ritual uncleanness described in Jewish halachic law. It is the highest grade of uncleanness, or defilement, and is contracted by having either directly or indirectly touched, carried or shifted a dead human body, or after having entered a roofed house or chamber where the corpse of a Jew is lying.
Leather is created when an animal skin or hide is chemically treated in a process called tanning to preserve them for long term use as material for clothing, handbags, footwear, furniture, sports equipment and tools. Alligator leather is also commonly used to create similar items as mentioned above.
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