Spring 2025

Vinegar has a long and storied history and plays a highly-prized role in every aspect of modern life – whether as a nutrient, flavorant, preservative or household cleanser. The name vinegar is derived from the French “vin aigre, which literally means sour wine. According to legend, its discovery is credited to a neglected barrel of wine that had been left in storage and allowed to ferment and become sour.

We find several references to vinegar in both Tanach and the Gemara. A nazir is forbidden to consume anything derived from grapes, which includes wine vinegar;[1] Dovid Hamelech accuses his tormentors metaphorically of giving him vinegar to quench his thirst;[2] Boaz’s workers dip their bread in vinegar;[3] and Mar Ukva refers to himself as “Chometz ben Yayin” – Vinegar, the son of Wine – when comparing himself to his father’s degree of piety.[4]

Vinegar Production

In Hebrew, the term for vinegar, chometz, shares a root with the word for leavened products, chametz, underscoring the connection between the production of vinegar and the leavening of bread.

Vinegar production involves three basic processes: two stages of fermentation, followed by one of filtration.

❶ Alcoholic fermentation: In this first stage, a sugary or starchy liquid (e.g., fruit juice, wine or beer) is fermented into alcohol by yeast, a fungus found in nature.

❷ Acetic acid fermentation (acetification): Next, the alcohol is further fermented into acetic acid, the main component of vinegar that gives it its sourness. There are two methods used for vinegar fermentation: the traditional vat method and the acetobactor generator process:

►Traditional Vinegar Fermentation: In this method, the alcoholic liquid – usually wine – is placed in custom-made oak barrel casks fashioned with numerous holes to allow for ample aeration. The alcohol in the wine is slowly converted into acetic acid. Once the desired level of alcohol is reached, the vinegar is ready.

In terms of kashrus, the obvious requirement is that the wine used in the processing is kosher, mevushal and controlled by Torah-observant workers throughout the production. Any additional ingredients must be kosher, as well. Furthermore, the casks used for the fermentation may not have been previously used to ferment non-kosher vinegar or wine.

►Acetobactor Generation: This system is used by modern-day vinegar manufacturers to produce large amounts of vinegar quickly and efficiently. The 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 as an external ingredient to be converted. The generators are filled with a solution of water, alcohol and vinegar from previous productions, along with bacteria (bactor), 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.

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; synthetic ethanol can be produced chemically. But ethanol can also be produced from potentially non-kosher materials. If the country of origin is a heavy producer of wine or grapes, there is a reasonable assumption that the imported alcohol was derived from grapes.

If a vinegar company uses grape-derived alcohol as their base product, all subsequent vinegar productions generated from this grape alcohol would be non-kosher. The repercussions of using non-kosher alcohol could be devastating. Vinegar is considered a davar charif – a product that is sharp and pungent. Since a davar charif is not batel b’shishim,[5] any condiments or sauces flavored or mixed with the non-kosher vinegar will be forbidden.

❸ Filtration. Each vinegar fermentation method undergoes a distinct filtration process:

► Traditional Filtration: Stainless-steel plates and paper filters are used to filter out large solid particles. The vinegar is further filtered through a microporous fiber membrane to remove any impurities, among them unwelcome residents of vinegar production: vinegar eels –  tiny nematodes that live in vinegar and typically reside in the vinegar barrels. These minute, round worms feed off the bacteria that produce the vinegar and can grow to a length of 1/16” to 3/8”. Filtration generally alleviates any chashash of vinegar eels. The end result is a final clear vinegar.

► Acetobactor Filtration: After being drawn off from the generator, the vinegar is filtered and standardized with water to its desired strength. In this process, diatomaceous earth and/or mechanical filters are used to remove any impurities, including vinegar eels discussed above.

Vinegar Strengths

The strength of the vinegar, known as grain, is determined by the percentage of acetic acid in the blend. 40 grain vinegar has 4% acidity, 50 grain has 5% acidity, and so forth. These are typically consumer-strength vinegars.

Industrial-strength vinegar can reach 200 grain acidity. Generally, industrial-strength vinegar is 120 grain, with 12% acidity. The raw materials used in the fermentation process play a fundamental role in the taste, color and fragrance of the vinegar variety.

What is Glacial Acetic Acid?

Increasingly, industrial food producers are turning to glacial acetic acid over vinegar in their productions. In the United States, acetic acid can be chemically derived more efficiently and economically than through a vinegar derivation. Are glacial acetic acid and vinegar synonymous, and are there kashrus concerns? And does the term acetic acid mean that it must be derived from vinegar? The answer to all of these is, no!

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. These processes do not present any kashrus concerns.

Acetic acid is vinegar’s sour component. It can be concentrated to different strengths. When the acetic acid is concentrated to 12% acidity, or 120 grain, 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.

Vinegar Types

There are numerous types of vinegar, each with their own processes and origins, including:

• White Distilled – from petroleum or fermented grains (e.g., corn, wheat); it is clear and tastes bitter
• Apple Cider – from fermented apples or cider; has an amber color and is more mellow
• Wine – from red or white wine; red wine vinegar has a deep red color
• Rice – from fermented rice; has a pale color and a mild flavor
• Malt – from fermented malted grains, such as barley or corn
• Balsamic – from fermented grape must
• Flavored – from infusions of herbs or fruit purees

Let’s take a closer look at these last two.

Balsamic Vinegar

Balsamic vinegar is a classic Italian favorite and an excellent example of a traditionally-aged vinegar. Whereas regular wine vinegar takes one or two years to ferment, the conversion of grape must – freshly pressed grape juice – to balsamic vinegar requires up to a dozen years to age.

The production of balsamic vinegar is a long and careful process. The grapes are gently crushed and aged in special chestnut or mulberry barrels where fermentation and oxidation occur simultaneously. As the vinegar evaporates, it is transferred to smaller cherry and mulberry barrels for further aging. At the end of the process, the balsamic vinegar is thick, full-bodied and almost condiment-like in consistency.

While authentic balsamic can require up to twelve years of aging, some of the premium balsamics used in this process are significantly older. In Modena, Italy, “mother” balsamic vinegars[6] can be traced back four centuries. Due to the complex task of tracing balsamic vinegar over such a long passage of time, authentic kosher balsamic is virtually impossible to verify.

A prized bottle of authentic balsamic vinegar can fetch between $150-$275 per 100 ml bottle.[7] The relatively inexpensive balsamic vinegar sold in the United States today is clearly not authentic balsamic. This mass-produced simulation consists of regular grape must mixed with balsamic wine flavoring and coloring, added to mimic the taste and appearance of authentic balsamic. The cheapest imitations are aged two years, a fraction of the time of true balsamic. Naturally, this shortcut is reflected in the price tag.

Infused Vinegar

One of the latest gastronomic trends borrowed from the recipe books of antiquity is the infusion of edible oils and vinegars. The original recipe as described in the Torah involves the compounding and mixing of the miraculous “anointing oil” of the Mishkan – the shemen hamishcha.[8] It was used when the meleches haMishkan neared completion and the keilim, bigdei kahuna and the kohanim themselves required special vesting of sanctity.

The principle, however, is the same: to give oil or vinegar a unique flavor through steeping them with herbs, spices, fruits or vegetables. As with any processed product, infused vinegars and oils require reliable kosher certification.

Halachic Questions Relating to Vinegar

►Are wine and wine vinegars created equal? There are many halachic differences between wine and wine vinegar. The bracha on wine is Borei Pri Hagafen, while the bracha on vinegar (in an edible state) is Shehakol.

Wine vinegar that was processed from stam yeinum (non-kosher wine or non-kosher grape juice) retains its non-kosher status. If an aino Yehudi touches non–mevushal wine, it becomes stam yayin and forbidden. Yet, kosher wine vinegar that was fermented under kosher conditions from non-mevushal wine does not become forbidden if touched by an akum.

► How do the laws of davar charif apply to vinegar? Halachically, vinegar is both charif and avida d’taima, sharp and pungent. Thus, it is halachically significant if a kosher product is soaked or mixed into vinegar versus into a sweet fruit juice. For instance, if a kosher product, such as a cucumber, is soaked in a non-kosher grape juice – halachically considered “mild” – the cucumber becomes non-kosher in 24 hours due to the principle of kavush kemevushal.[9] But, were it to be soaked in non-kosher wine vinegar, it becomes non-kosher in minutes – specifically, the time needed to boil the product, k’dei sheyartiach al ha’eish.[10]

► How do the laws of bitul (nullification) apply to vinegar? If non-kosher wine is inadvertently mixed into a kosher blend of fruit juices, the non-kosher wine is nullified if the ratio of non-kosher wine is less than 1:6 (i.e., one part in seven)  – the halachic ratio required to nullify non-kosher wine when it is mixed with water. As noted above, nullification does not apply, however, to something that is sharp. So if non-kosher vinegar is mixed into a kosher blend of fruit juices, the vinegar is not nullified due to the fact that it is an avida l’taima,[11] added for taste.

Special Vinegar Productions for Pesach

Pesach, of course, presents a host of new kashrus issues. All the fermentation ingredients have to be Kosher For Passover (KFP). The critical ingredient in KFP vinegar production is the KFP ethanol (grain alcohol). KFP ethanol can either be naturally derived from beet sugar or produced synthetically.[12]

If the ethanol is derived from barley, rye, oat, wheat or spelt, vinegar produced from these sources is chametz. If the grain alcohol is derived from corn, rice or milo (a corn derivative), the vinegar is kitniyos, and permissible for use by Sephardim, who eat kitniyos products on Pesach – provided that the other ingredients, such as the nutrients, are reliably KFP, as well.

The status of products using vinegar as an ingredient (e.g., ketchup, mustard, mayonnaise, salad dressing) depends on the grain used in their production. Grain alcohol in the U.S. is typically corn-based. In Europe, the grain alcohol may be chametz. This has ramifications with respect to the mitzvah of chametz she’avar alav haPesach. If the product is kitniyos, it does not need to be sold by Ashkenazim. But if the source is unknown, these vinegar-based products should be removed or sold with one’s chametz before Pesach by both Ashkenazim and Sephardim.

Vinegar-Flavored Kalamata Olives

The Mishna in Terumos[13] explains that there are two distinct categories of olives: oil-producing olives and table olives.

Table olives do not contain a natural abundance of oil but can be produced into a tasty condiment. In fact, the commentaries on this Mishna instruct us that to make table olives edible, they must be fermented in a strong brine solution for many months. The liquid is then poured off and the olives are mixed in a new brine solution with a lower salt content. 

Of the many regions that produce table olives, undeniably, the Kalamata region of Greece produces the “gold standard” table olive, hence, the name Kalamata olives. As you can imagine, the heralded recipe of classic Kalamata calls for wine vinegar.

To add flavor to table olives, vinegar is often added to the mix. Typically, olives that are produced as a commodity item are flavored with glacial acetic acid.  But to create an outstanding table olive, the old-world recipe calls for wine vinegar, which requires strict kosher supervision and is far more expensive than its non-kosher Greek counterpart.

Today, Kalamata olives are not limited to the Kalamata region in Greece any more than Bordeaux wine is limited to Bordeaux, France.  But without question, the ultimate flavored table olive is produced with wine vinegar.

Of course, there are industrial tricks of the trade. Economically, glacial acetic acid is far cheaper; moreover, after a short while, the brine turns purple and will look just like wine vinegar. Due to the similarity between glacial acetic acid and wine vinegar, there is a risk of substitution. Kashrus agencies, therefore, require hashgacha temidis for vinegar-flavored table olives.

Conclusion

Thinking about vinegar, its fascinating processes and myriad of uses, one can draw a profound life lesson from Hashem’s wonderful creation: there are times when one feels as though life has dealt them an unfair hand, yet we believe that things will eventually turn out for the best[14] – just as sour grapes turn into sweet success.

---

[1] Bamidbar 6:3.

[2] Tehillim 69:22.

[3] Rus 2:4.

[4] Chullin 105a.

[5] i.e., nullified if there is 60 times more kosher than non-kosher in the product, or a 1:60 ratio.

[6] A “mother” refers to a culture of beneficial bacteria and yeast that transforms alcohol into acetic acid, (i.e., vinegar).

[7] 100 ml is roughly 3 oz.

[8] The shemen hamischa was created to last for all eternity and is reserved for this one specific purpose; its “recipe” may never be duplicated.

[9] 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.

[10] Y.D. 105:2.

[11] 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.

[12] Kosher wine vinegar is typically KFP. Apple cider vinegar can also be produced KFP provided all of the ingredients are Passover-approved.

[13] Terumos 2:6.

[14] Brachos 60b:12 – kol d’avid Rachmana l’tav avid (everything Hashem does, He does for the best).