Tannic acid is a exact form of tannin, a type of polyphenol. Its weak acidity (pKa all 6) is due to the numerous phenol groups in the structure. The chemical way as a service to commercial tannic acid is often given as C76H52O46, which corresponds with decagalloyl glucose, but in information it is a amalgamating of polygalloyl glucoses or polygalloyl quinic acid esters with the horde of galloyl moieties per molecule ranging from 2 up to 12 depending on the spy documentation second-hand to distil the tannic acid. Commercial tannic acid is normally extracted from any of the following works parts: Tara pods (Caesalpinia spinosa), gallnuts from Rhus semialata or Quercus infectoria or Sicilian sumac leaves (Rhus coriaria).
According to the definitions provided in extraneous references such as international pharmacopoeia, Food Chemicals Codex and FAO-WHO tannic acid treatise at best tannins sourced from the above-mentioned plants can be considered as tannic acid. Every now extracts from chestnut or oak wood are also described as tannic acid but this is an faulty abuse of the term. It is a yellow to be disclosed brown amorphous powder.