Quebracho

Article By:

Strausbaugh, Perry D. Department of Botany, West Virginia University, Morgantown, West Virginia.

Core, Earl L. Department of Biology, West Virginia University, Morgantown, West Virginia.

Last reviewed:August 2020

DOI:https://doi.org/10.1036/1097-8542.564400

Any of a number of South American trees belonging to different genera but having similar qualities, with all being a valuable source of wood, bark, and tannin. Quebracho trees, including those of the genus Schinopsis (family Anacardiaceae) [see illustration], are indigenous to South America. In particular, the heartwood of Schinopsis lorentzii is called quebracho (meaning axbreaker in Spanish) in reference to its exceedingly hard wood, which is one of the hardest known woods. On average, the Janka hardness for quebracho is 4700 lb-force (2132 kg-force); its density is 80 lb/ft³ (1280 kg/m³). Quebracho is the world's most important source of tannin. The logs are chipped, and then the chips are cooked with steam in copper extractors. The liquor becomes highly concentrated, up to 40–60%, with tannin. It is used either alone or in combination with other chemicals for tanning of all kinds of leather. See also: Forest and forestry; Leather and fur processing; Sapindales; Tree

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