Tanbark

This article is about the type of bark used for tanning. For the form of mulch also known as "tanbark", seeBarkdust.For the neighborhood, seeTanbark, Le xing ton.

Workers peeling hemlock bark for the tannery inPrattsville, New York,United States

Tanbarkis thebarkof certain species of trees, traditionally used fortanninghidesintoleather.

The words "tannin","tanning","tan,"and"tawny"are derived from theMedieval Latintannare,"to convert into leather."

Bark millsare horse- or oxen-driven or water-powerededge millsand were used in earlier times to shred the tanbark to derive tannins for the leather industry. A "barker" was a person who stripped bark from trees to supply bark mills.

Tanbark around the world

Waterwheel at Combe House Hotel inHolford,Somerset, England.The overshot waterwheel was cast by Bridgwater ironfounder H Culverwell & Co in 1892 to replace an earlier wheel. It was used to grind oak bark for the tannery complex established here in the 1840s by James Hayman. When the tannery closed in 1900, the waterwheel was adapted to other uses, such as grinding grain forgrist,cuttingchaff,chopping apples for the cider press, and generating electricity. It also cracked stones in a nearby quarry. The gearing survives, too.

In Europe,oakis a common source of tanbark.Quercitannic acidis the chief constituent found in oak barks.The bark is taken from young branches and twigs in oakcoppicesand can be up to 4 mm thick; it is grayish-brown on the outside and brownish-red on the inner surface.

In some areas of the United States, such as central Pennsylvania and northernCalifornia,"mulch" is often called tanbark, even by manufacturers and distributors. In these areas, the word "mulch" may refer topeat mossor to very fine tanbark. In California,Notholithocarpus densiflorus(commonly known as thetanoakortanbark-oak) was used. In America,condensed tanninsare also present in the bark of blackjack oak (Quercus marilandica).InNew York,on the slopes ofMount Tremper,hemlockbark was a major source of tanbark during the 19th century.

Around theMediterranean Sea,sumach (Rhus coriaria) leaves and bark are used.

In Africa and Australia,acacia(called "wattle" ) bark is used by tanners. One ton of wattle ormimosabark produces about 150 lbs of puretannin.Used tanbark is employed in horticulture and spread on flower beds and in glass houses to keep down weeds and protect plant roots.

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  Tool to remove bark from oak branches
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  Removal of bark from oak branches
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  Another view of the process
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  The bark of an oak tree
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  Young red oak bark

See also

• Barkdust