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  • Sylvia Rose

Acetic Acid: Vinegar 🜊 in Ancient Alchemy

Acetic acid is a compound with many uses. With chemical formula CH₃COOH, this colorless liquid has a sharp pungent smell and sour taste. It's best known as the main component of vinegar. In the solution below, balsamic vinegar makes art in olive oil.



vinegar and oil
vinegar in oil

A staple in households worldwide, acetic acid has a long and varied history and expansive applications. A weak organic acid, it occurs naturally in various foods and is produced during the fermentation process, a favorite transformation method of alchemy.


An edged cross 🜊 is the alchemical symbol for vinegar in general. It's commonly seen in lists of alchemy symbols, in pharmacies and alchemic writings. The word "acetic" comes from Latin acētum (vinegar, or vinum acetum: "wine turned sour").



I'm not going to Delirius' party ... all he serves is vinum acetum.
"I'm not going to Delirius' party ... all he serves is his vinum acetum."

Vinegars have acetic acid concentrations from 4 - 6 % in regular white vinegar to 8% in some artisan brands and 18% in other applications. Acetic acid is made with a dual fermentation process, where yeast converts simple sugars into ethanol.


Acetic acid bacteria then transform ethanol into acetic acid. Acetic acid bacteria are a group of Gram-negative bacteria. They oxidize sugars or ethanol and produce acetic acid during fermentation.



Acetic acid bacteria much enlarged
Acetic acid bacteria much enlarged

Airborne, acetic acid bacteria are widely distributed in nature, especially where ethanol is produced through sugar fermentation. The bacteria can be found in flower nectar and damaged fruit, as well as in fresh apple cider and unpasteurized, unfiltered beer.


In these liquid environments, they form a surface film due to their aerobic characteristics and mobility. They are 10 genera of bacteria in family Acetobacteraceae.



pickled things

Fruit flies and vinegar eels are commonly recognized as carriers helping spread acetic acid bacteria. The growth of genus Acetobacter in wine can turn good booze to vinegar. In the 19th century, Louis Pasteur discovers the existence of the bacteria.


Acetic acid bacteria convert ethanol to acetic acid in the presence of oxygen. Bacteria of the genus Acetobacter have been isolated from industrial vinegar fermentation processes and are frequently used as fermentation starter cultures.



Vinegar Eels from a handbook for German housewives 1911
Vinegar Eels from a handbook for German housewives 1911

In winemaking, their activity can be reduced with sanitation and air-tightness of wine in storage. Use of moderate amounts of sulfur dioxide in the wine as a preservative also dissuades these industrious creatures.


Beyond culinary applications, vinegar has been used for centuries as a natural cleaning agent, food preservative, and as a health tonic due its sharp taste giving a feeling of invigoration.



leaping for joy

In pure form, acetic acid is hygroscopic (absorbs air moisture), a colorless liquid able to dissolve and interact with substances. While most often associated with vinegar, acetic acid can be synthesized chemically and is a key component in various industrial processes.


Also known as ethanoic acid, acetic acid is essential in processes of transformation. As a solvent, the acetic acid in vinegar it dissolves polar compounds such as inorganic salts and sugars, as well as non-polar compounds such as oils.



transformation in the light

The understanding of acetic acid and its properties further develops in the Middle Ages, particularly in alchemy. Alchemists often work with vinegar and see it as a manifestation of "sour", exploring transformative, preservative, purifying and corrosive powers of this acid.


While vinegar is a much diluted form, concentrated acetic acid is corrosive and attacks many metals. It forms flammable or explosive gases. It can also attack some forms of plastic, rubber and coatings.



"... did somebody say explosive?"
"... did someone say explosive?"

Alchemists seek to isolate elements and use natural processes to change their properties. One collective goal is to find a universal solvent. Vinegar is a popular, easily available acid. In the 1st century AD little is known about microscopic bacteria, but the process is intriguing.


While the making and doubling of gold is addressed in Alexandria, gold fever is more associated with the medieval, Renaissance and early modern age. It's less prevalent among the Alexandrian alchemists, who understand what gold making is all about.



Maria at work in the lab

Acids (waters), salts and other components are painstakingly separated from their parent compounds, purified and fortified. They might undergo further processing or are used raw in the alchemical methodology.


The history of acetic acid is older than most civilizations. Recorded use dates back to 5000 BCE in Mesopotamia. Acetic acid is discovered there as a byproduct of fermentation. Ancient Egyptians also use vinegar in food preservation and medicinal applications.



drawing of many potions

Alchemists know vinegar has the power to dissolve impurities, an important part of alchemy through the ages. For some, such as the Gnostics, purity of substances is mimicked as purity of soul/mind/body.


For all alchemists, experiments with acetic acid give a greater understanding of natural interactions. Combining vinegar with other substances, new compounds come to life, demonstrating the principles of chemical reactions.



apple cider vinegar
apple cider vinegar

While acetic acid is the most prominent component, vinegar contains other organic acids, including citric, malic, and tartaric acids. Today's vinegar contains various compounds to add flavor and aroma, including phenolics and esters.


The specific composition of vinegar also depends on its source. Apple cider, red wine, balsamic and rice vinegar all have unique profiles offering distinct culinary experiences.

Combination of these elements gives vinegar its diverse applications and health benefits.



Industrial capacity vinegar production
Industrial capacity vinegar production

Applications of Acetic Acid


Acetic acid is versatile and used in various industries:


  1. Food Industry: Besides being a primary component of vinegar, acetic acid is used as a food preservative, flavoring agent, and acidulant in products such as sauces, pickles, and canned goods.

  2. Medicine: Acetic acid is used in certain medical applications, including in the preparation of some medications and as an antiseptic.

  3. Chemicals: It is central to the production of chemicals like acetates, which are used in the manufacture of plastics, dyes, and solvents.

  4. Agriculture: Acetic acid is utilized as a herbicide and pesticide, proving effective against certain unwanted plants or insects.

  5. Textiles: In artisan dyeing it can be used as a pre-mordant together with citric acid. This may have led to the myth vinegar can be used as a mordant for home dyeing. Neither vinegar nor acetic acid are good main mordants. Colors wash out very quickly. In industry acetic acid may be used with other substances as part of the dye process.

  6. Hair Dye: it may extend the color life of dyed hair if applied before dyeing.



many hair colors
many shades of hair

According to hair care experts vinegar works on the hair like a mordant:

“Vinegar is a clarifier—it helps with removing buildup on the cuticle layer of the hair. A vinegar rinse before applying semi-permanent color will help the color adhere and therefore last longer. A vinegar rinse after applying semi-permanent color will strip some of the color off.”

Acetate is a bio-plastic or biodegradable plastic derived from biological substances rather than from petroleum. It's extracted from cellulose, a plant based material from wood pulp, mixed with acetic acid. So acetate as an ecologic solution can involve chopping a lot of trees.


It's almost like making electric car batteries with lead and sulfuric acid. Whoever would do that?



electric car

Health Benefits and Wellness Trends


Acetic acid, particularly in apple cider vinegar, is lauded by purveyors as a health tonic with miraculous benefits ranging from weight loss aid to blood sugar regulation. Scientific studies are inconclusive.


Some potential benefits include:


  1. Blood Sugar Regulation: Studies suggest that vinegar may help improve insulin sensitivity and reduce blood sugar levels post-meal, making it a potential ally for managing type 2 diabetes.

  2. Weight Management: Some research has indicated that vinegar consumption may promote feelings of fullness, potentially aiding in weight loss efforts.

  3. Antimicrobial Properties: The antibacterial properties of acetic acid make it effective in killing harmful bacteria, which can contribute to food safety.

  4. Heart Health: Preliminary findings suggest that acetic acid may help lower cholesterol levels and blood pressure, contributing to cardiovascular health.



... it's used for heart health
... it's used for heart health

Trade and Commerce


The trade of vinegar, and by extension acetic acid, plays a vital role in various cultures, from the Mediterranean to Asia. Historically, vinegar is valuable as a culinary ingredient, preservative and a medicine. Verjuice, a weak type of vinegar, is popular in cuisine.


Acetic acid's ability to inhibit bacteria growth makes it a vital food preservative, especially in the long millennia before refrigeration. Trade routes of the ancient world include vinegar as a commodity. Production techniques are refined to the many types of vinegar today.



Many types of condiments - vinegar bottom shelf
Many types of condiments - vinegar bottom shelf

Non-Fiction Books:


Fiction Books:

READ: Lora Ley Adventures - Germanic Mythology Fiction Series

READ: Reiker For Hire - Victorian Detective Murder Mysteries








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