Vinegar is one of nature’s most unique and versatile products. Folklore maintains that vinegar was discovered quite by accident, when wine was inadvertently left to sour. This resulted in the first batch of full-bodied wine vinegar. Indeed, the word ‘vinegar’ is derived from the French word vinaigre, which means sour wine. Euphemistically, the Talmud refers to a ne’er-do-well son of a righteous father as a Chometz Ben Yayin, “vinegar son of wine.”
Folklore aside, vinegar was well known in the time of Tanach. The Torah forbids a Nazir to drink wine vinegar or eat other grape and wine products. In Tehillim,¹ Dovid Hamelech asked to drink vinegar when he said, “Vlitzmaie Yashkuni Chometz”. In Megilas Rus, Boaz’s workers dipped their bread in vinegar.²
The Hebrew term for vinegar, chometz (pronounced ch-oh-metz), is similar to the word chametz (pronounced ch-aw-maitz), leavened bread products. This etymological similarity underscores the correlation between the production of vinegar and the leavening of bread. The chemical process that allows wine to “sour” into vinegar, effecting the leavening of flour and water, is known as fermentation. Fermentation is a natural conversion process by which yeast, a fungus found in nature, converts sugar into alcohol and carbon dioxide. In wine or bread the natural sugar found in malted grains, such as barley or corn, or in fruit juices ,such as grape juice or apple cider, undergoes this chemical transformation.
To create vinegar, a second fermentation process has to take place. In this process, bacteria converts the alcohol into acetic acid, the sour element of vinegar. There are two methods used for vinegar fermentation: the traditional vat method and the acetobactor generator process.
In traditional vinegar fermentation, the alcoholic liquid – usually wine – is placed in specially made oak barrel casks with plenty of air holes to allow for ample aeration. The alcohol in the wine is slowly converted into acetic acid until the proper level is reached. Once this takes place, the vinegar is ready. A classic Italian favorite, balsamic vinegar, is an excellent example of a traditionally aged vinegar. Whereas regular wine vinegar takes one or two years to ferment, the conversion of grape (juice) to balsamic vinegar requires 12 years to age.

The production of balsamic vinegar involves a long and careful process. The grapes have to be carefully crushed and are aged in special chestnut or mulberry barrels where fermentation and oxidation occur simultaneously. As the vinegar ages and evaporates, the vinegar is transferred to smaller cherry and mulberry barrels for further conversion. After 12 years, the balsamic vinegar is thick, full-bodied and almost condiment-like in consistency. Authentic balsamic requires as much as 12 years of aging; however, some of the mother balsamics used in this process are much older. In Modena, Italy, mother balsamic vinegars can be traced back 400 years. Due to the complex task of tracing balsamic vinegar through the matrix of time, authentic kosher balsamic would be nearly impossible to trace.
A prized bottle of authentic balsamic vinegar can fetch between $150-$275/100ml bottle! Today, the mass-produced balsamic vinegar sold in the United States is not authentic balsamic. In reality, it is regular grape must (the freshly pressed grape juice) with balsamic wine flavoring and coloring that captures the taste and appearance of authentic balsamic. The cheapest imitations are hardly aged; medium grades are aged two years, a fraction of the time of balsamic vinegar. Of course, this shortcut is reflected in the price tag.
Modern day vinegar companies use the acetobactor generator system to produce large amounts of vinegar quickly and efficiently. These generators range in size from 6,000 to 18,000 gallons. The word acetobactor is a contraction of two Italian words: Aceto (vinegar) and bactor (bacteria). Bactor refers to the bacteria used in these generators to convert the alcohol into acetic acid. In lieu of fermentation, 190-proof alcohol is brought in from outside sources to be converted. The generators are filled with a solution of water, alcohol and vinegar from previous processing, bacteria, bacteria food nutrients, and beechwood shavings. The generator is kept at a constant 85°F. The alcohol circulates through the generator and is converted into acetic acid. After being drawn off from the generator, the vinegar is filtered and standardized with water to its desired strength.
The strength of the vinegar, known as grain, is determined by the percent of acetic acid in the blend. 40 grain vinegar means that there is 4% acidity, 50 grain means that there is 5% acidity, etc. These are typically consumer strength vinegars. Industrial strength vinegar can go up to 200 grain acidity. Industrial strength vinegar is generally 12% acidity, or 120 grain. The raw materials used for the fermentation process play a fundamental role in the taste, color and fragrance of the vinegar variety. White distilled vinegar is made from petroleum or grains, such as corn and wheat; it is clear and tastes bitter. Apple cider vinegar is much more mellow and has an amber color; red wine vinegar has a much deeper red color.

Glacial Acetic Acid-Synthetic Vinegar
Today, a product known as glacial acetic acid is used in industrial food production. What is meant by this term? Are glacial acetic acid and vinegar synonymous, and are there kashrus concerns?
Acetic acid is vinegar’s sour component. Acetic acid can be concentrated into different strengths. When the acetic acid is concentrated to a strength of 12% or 120 grain level, the acetic acid will freeze at 16.7°C (62°F). Acetic acid that possesses this property is commonly known as glacial acetic acid. The term “glacial” indicates a product that reaches this high freezing point.
Does the term “acetic acid” mean that it must be derived from vinegar? The answer is NO! It is a known fact that in the United States, acetic acid can be derived chemically more efficiently and economically than through a vinegar derivation. Industrial glacial acetic acid is typically produced through a chemical reaction of methanol (a petroleum derivative) and carbon monoxide, or through oxidation methods of synthetic acetaldehyde, and would not present any kashrus concerns.

THE HALACHIC ISSUES
Are Wine and Wine Vinegar Created Equal?
There are many halachic differences between wine and wine vinegar. The brocha one makes on wine is Borei Pri Hagafen; the brocha on vinegar in an edible state is Shehakol. Obviously, wine vinegar that was processed from stam yaynum (non-kosher wine or non-kosher grape juice) would retain its non-kosher status. If an akum (non-Jew) touches non-mevushal wine it would become stam yayin, and would be forbidden. Yet, kosher wine vinegar that was fermented under kosher conditions from non-mevushal wine does not become forbidden if touched by an akum.
Good Vinegar Manufacturing Practices
Utilizing the traditional method of wine vinegar fermentation, the obvious requirement that must be met is that the kosher wine used in processing is mevushal and controlled by Torah observant workers throughout production. Any additional ingredients must be kosher, as well. Furthermore, the casks used to ferment kosher vinegar may not have been previously used to ferment non-kosher vinegar or wine.
In the acetobactor generator process, a wide array of alcohols can be used for the conversion process. These alcohols may be derived from a variety of sources. Natural ethanol can be derived from corn, wheat or sugar and synthetic ethanol can be produced chemically. Ethanol can be produced from other materials, as well. If the country of origin for the ethanol is a heavy producer of wine or grapes, there is a reasonable assumption that the imported alcohol could be derived from grapes. In that case, if the vinegar company uses grape-derived alcohol as their base product all the subsequent vinegar productions generated from this grape alcohol would be non-kosher! The repercussions of using non-kosher alcohol would be devastating. Vinegar is considered a davar charif product that is very sharp and pungent. Since a davar charif will not be nullified in a mixture of a 1 to 60 ratio, all of the product’s condiments or sauces that were flavored or mixed with the non-kosher vinegar may also be forbidden.

IN THE KITCHEN
Some Like It Hot: Davar Charif
Halachically, vinegar is considered to be a product that is both charif and avida d’taima, sharp and pungent. It is of halachic significance whether a kosher product was soaked or mixed into sharp vinegar or mild juices. If a kosher product, such as a cucumber, would be soaked in a ‘mild’ non-kosher grape juice, the cucumber would become non-kosher in 24 hours due to the principle of kavush kemevushal.³ However, if a cucumber was soaked in non-kosher wine vinegar it would become non-kosher in the time needed to boil the product, k’dei sheyartiach al ha’eish.⁴
Bitul – Nullification
If non-kosher wine was inadvertently mixed into a kosher blend of fruit juices, the non-kosher wine would be nullified if the percentage of non-kosher wine was less than a 1 to 6 part ratio. This is the halachic ratio needed to nullify non-kosher wine when it is mixed with water. However, the sharp tasting pungency of vinegar would not allow the wine vinegar to become nullified due to the fact that vinegar is a product that is avida l’taima,⁵ added for taste.

VINEGAR GOING KFP
Pesach, of course, presents a new host of kashrus issues. All of the fermentation ingredients have to be kosher for Pesach (KFP). The critical ingredient used in Kosher l’Pesach vinegar production is Kosher l’Pesach ethanol (alcohol). Kosher l’Pesach ethanol can be either naturally derived from beet sugar or produced synthetically.⁶
If the ethanol (grain alcohol) comes from barley, rye, oat, wheat or spelt, the vinegar produced from these sources would also be considered chametz. However, if the grain alcohol is derived from corn, rice or milo (a corn derivative), the vinegar is not considered chametz but is considered kitniyos. This vinegar would not be permitted for use by Ashkenazic Jews on Pesach but may be used by Sephardic Jews (who eat kitniyos products on Pesach), provided that the other ingredients, such as the nutrients, are reliably kosher for Pesach, as well.
Chometz She’avar Alav HaPesach
The halacha is clear that it is forbidden for a Jew to possess chometz on Pesach. Chometz products must be consumed, destroyed or sold to a non-Jew in a bona fide sale, transferring it out of Jewish ownership before Pesach. Failing to do so would render the unsold chometz forbidden for Jewish consumption even after Pesach.
Is grain vinegar, or a product using grain vinegar as an ingredient, considered chometz? In order to provide the kosher consumer accurate pre-Pesach information regarding the chometz or non-chometz status of products using vinegar as an ingredient (i.e., ketchup, mayonnaise, salad dressing or mustard), STAR-K researches the various vinegar producers and their sources of supply of startup material from U.S. grain alcohol producers. Typically, grain alcohol in the U.S. is corn-based. In Europe, the grain alcohol may be chometz. If the source is unknown, these vinegar-based products should be used, removed or sold with one’s chometz.
What about purchasing products using vinegar after Pesach? Since it is a reasonable assumption that in the U.S., products using domestic grain vinegar are predominantly kitniyos-based, we are permitted to create a halachic assumption employing the principle of ‘Holchin Achar Harov’, which states that we can reasonably assume that these products in question are kitniyos-based. Since chometz she’avar alav haPesach is a din d’rabonon,⁷ a rabbinical enactment, we are permitted to rule leniently. In the case of a sofek d’rabonon, we rule leniently⁸ – sofek d’rabonon l’kula. Therefore, these products do not present post-Pesach chometz concerns and may be purchased immediately after Pesach.
Vinegar Eels
The last step of vinegar production is filtration through diatomaceous earth and/or mechanical filters to remove any impurities. Vinegar filtration is needed to remove unwelcome residents of vinegar production, namely vinegar eels.
What are vinegar eels? Vinegar eels are tiny nematodes, round worms that live in vinegar. They are usually found in vinegar barrels and feed off the bacteria that produce the vinegar. Vinegar eels are slender and grow to a length of 1/16” to 3/8”. Filtration would generally alleviate any chashash of vinegar eels.

CONCLUSION
It is indeed amazing to uncover the niflaos haboreh, Hashem’s wonders, and how they manifest themselves in so many commonplace areas. Just as vinegar enhances food, it also enhances our appreciation of Hashem’s bounty and the gifts provided by nature.

1. Tehillim 69:22 – ץמוח ינוקשי יעמצלו
2. Rus 2:4
3. Y.D. 105:1. This principle states that it takes 24 hours for a kosher product soaking in a mild non-kosher liquid to be imbued with the liquid’s non-kosher properties. A sharp or pungent liquid, ‘davar charif’, would achieve its goal much more quickly.
4. Y.D. 105:2
5. Y.D. 98:8 Rema, Taz 11. The principle of something that is avida l’taima is not batel b’shishim as long as one can taste the vinegar.
6. Kosher wine vinegar is typically Kosher L’Pesach. Apple cider vinegar can also be produced Kosher L’Pesach, provided all of the ingredients are Passover approved.
7. A rabbinic enactment
8. Sofek d’rabonan l’kula