Pyroligneous acid[1][2]
Other names
wood vinegar and wood acid
ECHA InfoCard 100.029.495 Edit this at Wikidata
EC Number
  • 232-450-0
Appearance Yellow to red liquid
Odor acrid smoky
Density 1.08 g/mL
Boiling point 99 °C (210 °F; 372 K)
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
H226, H312, H315, H319, H335
Flash point 44 °C (111 °F; 317 K)
Related compounds
Related compounds
Liquid smoke
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Pyroligneous acid, also called wood vinegar or wood acid,[3] is a dark liquid produced by the destructive distillation of wood and other plant materials.


The principal components of pyroligneous acid are 10% acetic acid, acetone and methanol. It was once used as a commercial source for acetic acid.[citation needed]


Pyroligneous acid (acetum lignorum) was investigated by German chemist Johann Rudolph Glauber.[4] The acid was used as a substitute for vinegar. It was also used topically for treating wounds, ulcers and other ailments. A salt can be made by neutralizing the acid with a lye made from the ashes of the burnt wood.[5]

During the United States Civil War it became increasingly difficult for the Confederate States of America to obtain much needed salt. Curing meat and fish with pyroligneous acid was attempted by cooks to compensate for this deficiency, but it was insufficient.[6]

In the nineteenth century, pyroligneous acid was used to prepare an impure aluminium sulfacetate mordant for use with cotton, but the resulting mixture imparted a burnt odor to the cotton, and Ganswindt recommended its use be abandoned in favour of purer preparations in 1899.[7]

In 1895, pyroligneous acid was first marketed under the brand Wright's Liquid Smoke,[8] a liquid smoke product intended to impart the flavor and some of the preservative effects of wood smoking to meats and vegetables. In the early 21st century, concerns about the carcinogenic effects of components of wood smoke decreased the production of heavily smoked foods in favor of lighter smoking and liquid smoke for foods.[9]


  1. ^ Pyroligneous acid from Sigma-Aldrich
  2. ^ George A. Burdock (2010), "PYROLIGNEOUS ACID", Fenaroli's Handbook of Flavor Ingredients (6th ed.), Taylor & Francis, pp. 1774–1775, ISBN 978-1-4200-9077-2
  3. ^ Webster's Revised Unabridged Dictionary (1913)
  4. ^ Fielding H. Garrison (1921), History of Medicine (3rd ed.), W. B. Saunders, p. 286
  5. ^ Johann Rudolph Glauber (1651), Furni Novi Philosophici, vol. 1, Johann Jansson, pp. 47–49
  6. ^ Mark Kurlansky (2002). Salt: A World History. Penguin Books. pp. 267–68. ISBN 0-14-200161-9.
  7. ^ Ganswindt, Albert (1889). Handbuch der Färberei und der damit verwandten vorbereitenden und vollendenden Gewerbe (in German). p. 270.
  8. ^ Unusual Stories of Unusual Men: Ernest H. Wright - Classification: "Condensed Smoke". The Rotarian. 1923. pp. 209–10, 240.
  9. ^ Bruce Kraig (31 January 2013). The Oxford Encyclopedia of Food and Drink in America. OUP USA. pp. 2–. ISBN 978-0-19-973496-2.