Chestnut tannin extract was used extensively in France and other European countries, as well as in the United States, in the latter part of the 19th century and early 20th century. Today Italy is the largest producer of chestnut wood extract for tanning. The bark of the chestnut is not used because it imparts a dark color to the tannin, and its high sugar content would result in a higher percentage of soluble non-tans in the extract. The wood does not seem to reach its highest tannin content until the trees are at least 30 years old. Chestnut extract tans rapidly and produces a firm leather.
Chestnut is one of the pyrogallol class of tannins, and has a naturally low pH value.
It also has a relatively low salts content and a high acids content.