Pyroligneous acid, also called wood vinegar or wood acid, is a dark liquid produced by the

destructive distillation Destructive distillation is a chemical process in which decomposition of unprocessed material is achieved by heating it to a high temperature; the term generally applies to processing of organic material in the absence of air or in the presence o ...

of wood and other plant materials.

Composition

The principal components of pyroligneous acid are 10%

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main compone ...

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

and

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

. It was once used as a commercial source for acetic acid.

History

Pyroligneous acid (acetum lignorum) was investigated by German chemist Johann Rudolph Glauber. The acid was used as a substitute for vinegar. It was also used topically for treating wounds, ulcers and other ailments. A

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

can be made by neutralizing the acid with a

lye Lye is the common name of various alkaline solutions, including soda lye (a solution of sodium hydroxide) and potash lye (a solution of potassium hydroxide). Lyes are used as cleaning products, as ingredients in soapmaking, and in various other c ...

made from the ashes of the burnt wood. During the

United States Civil War The American Civil War (April 12, 1861May 26, 1865; also known by other names) was a civil war in the United States between the Union ("the North") and the Confederacy ("the South"), which was formed in 1861 by states that had seceded ...

it became increasingly difficult for the

Confederate States of America The Confederate States of America (CSA), also known as the Confederate States (C.S.), the Confederacy, or Dixieland, was an List of historical unrecognized states and dependencies, unrecognized breakaway republic in the Southern United State ...

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. In the nineteenth century, pyroligneous acid was used to prepare an impure aluminium sulfacetate

mordant A mordant or dye fixative is a substance used to set (i.e., bind) dyes on fabrics. It does this by forming a coordination complex with the dye, which then attaches to the fabric (or tissue). It may be used for dyeing fabrics or for intensifying ...

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. In 1895, pyroligneous acid was first marketed under the brand Wright's Liquid Smoke, a

liquid smoke Liquid smoke is a water-soluble yellow to red liquid used as a flavoring as a substitute for cooking with wood smoke while retaining a similar flavor. It can be used to flavor any meat or vegetable. It is available as pure condensed smoke from ...

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.

References

External links

AcidWorks
{{portal bar, Food Wood Organic acids Vinegar