29 BEVERAGE & FOOD WORLD NOVEMBER 2012
Vinegar Production Technology – An Overview
Simon Hailu, Shimelis Admassu and Yogesh Kumar Jha
Food Process Engineering Program, Department of Chemical Engineering,P.0.Box:385, Addis Ababa Institute of Technology (AAiT), Addis Ababa University, Ethiopia
Vinegar is an acid liquid produced from the fermentation of ethanol
in a process that yields its key ingredient, acetic acid (ethanoic acid).
The acetic acid concentration typically ranges from 4% to 8% by
volume for table vinegar and up to 18% for pickling. Natural vinegars
contain small amounts of tartaric acid, citric acid, and other acids.
Vinegar has been used since ancient times and is an important
element in European, Asian, and other cuisines. The word “vinegar”
derives from the Old French vin agre, meaning “sour wine”. Vinegar
has been made and used for thousands of years. Traces of it have
been found in Egyptian urns dating from around 3000 BC. In 1864,
Louis Pasteur showed that vinegar results from a natural fermentation
Vinegar is primarily used to flavor and preserve foods and as an
ingredient in salad dressings and marinades. Vinegar is also used
as a cleaning agent. Natural vinegar is a superior food additive over
synthetic vinegar as it carries essential amino acids from its fruit
source and is reported to act as a medicine for aches and gastric
troubles. However, it is generally ignored by both the consumer (due
to the higher price) and the producer (due to the long fermentation
time of 5–6 weeks). Moreover, vinegar can be more than an addition
to any dish; it can be a source of income, a promising business.
In this paper work aims to elaborate the different types of vinegars
and major vinegar processing methods used for commercial
production. As an example a flow chart for the production of cane
vinegar is included and possible improvements for cane vinegar
production are discussed.
There are many different types of vinegars. The classification is usually
based on the raw material used for its production. Malt vinegar, Wine
vinegar, Apple cider vinegar, Balsamic vinegar, Fruit vinegar and many
other types of vinegar exist in today’s global market. The most common
types of vinegars and their origin are discussed below.
Wine vinegar is made from red or white wine and is the most commonly
used vinegar in Mediterranean countries and Central Europe. As with
wine, there is a considerable range in quality. Better quality wine vinegars
are matured in wood for up to two years and exhibit a complex, mellow
flavor. Wine vinegar tends to have a lower acidity than that of white or
cider vinegars. There are more expensive wine vinegars that are made
from individual varieties of wine, such as Champagne, Sherry, or pinot
Vinegar made from beer is produced in the United Kingdom,
Germany, Austria, and the Netherlands. Although its flavor depends
on the particular type of beer from which it is made, it is often
described as having a malty taste. That produced in Bavaria, is a
light golden color with a very sharp and not-overly-complex flavor.
In Beer vinegar and Wine vinegar production only one type of
fermentation takes place; for the conversion of ethanol in to acetic
acid. But other types of vinegars, discussed later, are grouped under
a production process where there are two types of fermentations;
one for ethanol formation and another conversion of the ethanol in
to acetic acid.
Fruit vinegars are made from fruit wines, usually without any additional
flavoring. Common flavors of fruit vinegar include apple, black currant,
raspberry, quince, and tomato. Typically, the flavors of the original fruits
remain in the final product. Most fruit vinegars are produced in Europe,
where there is a growing market for high-priced vinegars made solely
from specific fruits (as opposed to non-fruit vinegars which are infused
with fruits or fruit flavors). Several varieties, however, also are produced
in Asia. Persimmon vinegar, called gam sikcho is popular in South Korea.
Jujube vinegar and wolfberry vinegar are produced in China. Jamun
Sirka is vinegar produced from the Jamun (or rose apple) fruit in India. It
is considered to be medicinally valuable for stomach, spleen and diabetic
Balsamic vinegar is an aromatic, aged type of vinegar traditionally crafted
in the Modena and Reggio Emilia provinces of Italy from the concentrated
juice, or must, of white grapes (typically of the Trebbiano variety). It is
very dark brown in color and its flavor is rich, sweet, and complex, with
the finest grades being the product of years of aging in a successive
number of casks made of various types of wood (including oak, mulberry,
chestnut, cherry, juniper, ash, and acacia). Originally a product available
only to the Italian upper classes, a cheaper form of balsamic vinegar
became widely known and available around the world in the late twentieth
century. True balsamic vinegar (which has Protected Designation of
Origin) is aged for 12 to 25 years. Balsamic vinegars that have been
aged for up to 100 years are available, though they are usually very
expensive. The commercial balsamic sold in supermarkets is typically
made with concentrated grape juice mixed with strong vinegar, which is
laced with caramel and sugar. Regardless of how it is produced, balsamic
vinegar must be made from a grape product. Balsamic vinegar has a
high acidity level but the tart flavor is usually hidden by the sweetness of
the other ingredients, making it very mellow.
Malt vinegar is made by malting barley, causing the starch in the grain to
turn to maltose. Then ale is brewed from the maltose and allowed to turn
into vinegar, which is then aged. It is typically light brown in color.
Rice vinegar is most popular in the cuisines of East and Southeast Asia.
It is available in “white” (light yellow), red, and black varieties. The
Japanese prefer light rice vinegar for the preparation of sushi rice and
salad dressings. Red rice vinegar traditionally is colored with red yeast
rice. Black rice vinegar (made with black glutinous rice) is most popular
in China, and it is also widely used in other East Asian countries. White
rice vinegar has a mild acidity and a somewhat “flat”, uncomplex flavor.
Some varieties of rice vinegar are sweetened or otherwise seasoned
with spices or other added flavorings.
Coconut vinegar, Palm vinegar, Raisin Vinegar, Honey Vinegar,
Sugar Cane Vinegar and many other different types of vinegar are
produced in different parts of the world. The Coconut vinegar, a cloudy
white liquid, with a sharp acidic taste is famous in Southeast Asian
cuisine, particularly in the Philippines. Palm vinegar is another type
most often used in the Philippines, where it is produced. Vinegar
made from raisins called khal ‘anab in Arabic is used in cuisines of
30 BEVERAGE & FOOD WORLD NOVEMBER 2012
C6H12O6 (Glucose) 2C2H5OH (Ethyl Alcohol) + 2CO2 + Energy
2C2H5OH (Ethyl Alcohol)+O2 CH3COOH(Acetic Acid) + H2O + Energy
the Middle East. Though Vinegar made from honey is rare,
commercially available honey vinegars are produced in Italy, France,
Romania and Spain.
3. VINEGAR PRODUCTION
3.1. Raw Materials
The major raw materials for the production of vinegar are alcohol
containing liquid, Acetobacter, a genus of aerobic bacteria, oxygen,
and some times herbs and fruits as a flavoring agent.
Alcohol Containing Liquid
Vinegar can be made from a variety of diluted alcohol products, the
most common being wine and beer. Alternatively an alcohol product
can be prepared through fermenting carbohydrate in rice, sugar cane,
or malt anaerobically by yeast. The resulting alcohol product is
pasteurized, filtered and then diluted to adjust the alcohol content
and then used for vinegar production.
Acetobacter acetii cultures are used for vinegar production. These
perfectly work at a temperature of 28 °C (82 °F) with full air injection.
The lowest temperature that the bacteria can tolerate is 20 °C
(68 °F) and the maximum temperature is 33 °C (91 °F). Below and
above these temperatures, there is no conversion from alcohol into
acetic acid. The starting alcohol should be lower than 7.5 % (v/v)
and there should be no free Sulfites.
In the natural processes, Acetobacters are allowed to grow over
time. However, mother of vinegar is added as a source of Acetobacter
for commercial production. Mother of vinegar is the gooey film that
appears on the surface of the alcohol product as it is converted to
vinegar. Mother of vinegar is skimmed off the top and added to
subsequent batches of alcohol to speed the formation of vinegar. It
consist natural carbohydrate called cellulose and this film holds the
highest concentration of Acetobacters. Sometimes in the vinegar
factory acetozym nutrients are added in to the alcohol liquid as a
bacterial culture. Acetozym nutrients are manmade powdered form
of mother of vinegar.
Herbs and fruits are often used to flavor vinegar. Commonly used
herbs include tarragon, garlic, and basil. Popular fruits include
raspberries, cherries, and lemons.
Vinegar is the product obtained as a result of impartial oxidation of
alcohol in a fermenting sugar containing fruit or cane juice, molasses,
fermented mash of malted grain, honey, syrups, etc. It is made from
the fermentation of ethanol by acetic acid bacteria. The ethanol may
be derived from many different sources including wine, cider, beer
or fermented fruit juice. For wine vinegar and beer vinegar the
production process only includes fermentation for the conversion of
the alcohol present in the raw materials in to acetic acid. However,
in other types of vinegar such as fruit vinegars or cane vinegars two
major processing steps are carried out; one for the production of
ethanol alcohol from raw materials and the other for the conversion
of the ethanol produced in to acetic acid. Vinegar contains, mainly,
acetic acid by weight and small quantities of alcohol, glycerol, easters,
sugars, and salts. To find pure acetic acid the vinegar is subjected
to purification by distillation.
The transformation of wine or fruit juice to vinegar is a chemical
process in which ethyl alcohol undergoes partial oxidation that results
in the formation of acetaldehyde. Then, the acetaldehyde is converted
into acetic acid. Thus, it can be said that the production of vinegar
involves two types of biochemical reactions: alcoholic fermentation
and oxidation of alcohol in to acid.
Alcoholic fermentation of carbohydrate is the first critical step in
the production of vinegar and takes place under anaerobic condition.
In this step sugar is fermented to alcohol by the action of yeast species
Oxidation of alcohol to acid is the second major step in the
production of vinegar and is aerobic process. In this step alcohol is
oxidized to acetic acid by the action of acetic bacteria; the species of
Commercial vinegar is produced either by fast or slow fermentation
processes. In the slow, or natural, process, vats of cider are allowed
to sit open at room temperature. During a period of several months,
the fruit juices ferment into alcohol and then oxidize into acetic acid.
Slow methods generally are used with traditional vinegars;
fermentation proceeds slowly over the course of weeks or months.
The longer fermentation period allows for the accumulation of a
nontoxic slime composed of acetic acid bacteria and soluble cellulose,
known as the mother of vinegar.
Fast methods add mother of vinegar (i.e., bacterial culture) to the
source liquid before adding air using a Venturi pump system or a
turbine to promote oxygenation to obtain the fastest fermentation. In
fast production processes, vinegar may be produced in a period
ranging from 20 hours to three days. In the modern commercial
production of vinegar, the generator method and the submerged
fermentation method are employed. These methods are based on
the goal of infusing as much oxygen as possible into the alcohol
The three common methods used for vinegar production are the
generator or trickling method, the submerged fermentation or the
Acetator method and the Orleans traditional method. Traditionally
natural spontaneous fermentation is also used. The Generator
method is the quicker one and is generally used in commercial vinegar
3.1.1. The Orleans Method
The Orleans process is one of the oldest and well known methods
for the production of vinegar. It is a slow, continuous process, which
originated in France. High grade vinegar is used as a starter culture,
to which wine is added at weekly intervals. The vinegar is fermented
in large (200 liter) capacity barrels. Approximately 65 to 70 liters of
high grade vinegar is added to the barrel along with 15 liters of wine.
After one week, a further 10 to 15 liters of wine are added and this is
repeated at weekly intervals. After about four weeks, vinegar can be
withdrawn from the barrel (10 to 15 liters per week) as more wine is
added to replace the vinegar. One of the problems encountered with
this method is that of how to add more liquid to the barrel without
disturbing the floating bacterial mat. This can be overcome by using
a glass tube which reaches to the bottom of the barrel. Additional
liquid is poured in through the tube and therefore does not disturb
the bacteria. Wood shavings are sometimes added to the fermenting
barrel to help support the bacterial mat.
1) Wooden barrels are laid on their sides. Bungholes are drilled
into the top side and plugged with stoppers. Holes are also drilled
into the ends of the barrels.
2) The alcohol is poured into the barrel via long-necked funnels
inserted into the bungholes. Mother of vinegar is added at this
point. The barrel is filled to a level just below the holes on the
ends. Netting or screens are placed over the holes to prevent
insects from getting into the barrels.
3) The filled barrels are allowed to sit for several months. The room
temperature is kept at approximately 85°F (29°C). Samples are
taken periodically by inserting a spigot into the side holes and
drawing liquid off. When the alcohol has converted to vinegar, it
is drawn off through the spigot. About 15% of the liquid is left in
the barrel to blend with the next batch.
3.1.2. The Generator Method
Because the Orleans process is slow, other methods have been
adapted to try and speed up the process. This method uses a
generator (figure 1), which is an upright tank filled with beech wood
shavings and fitted with devices which allow the alcoholic solution to
trickle down through the shavings in which the acetic acid bacteria
Generators of various sizes (15 feet in diameter and 20 feet in
31 BEVERAGE & FOOD WORLD NOVEMBER 2012
length) are used. The generator consists of a cylindrical tank with a
perforated false bottom supporting beech-wood shavings or similar
material that will help increase the flow of air from this bottom that
has an exit at the top. A mix is prepared which consist of an adjusted
solution of alcohol acidified with acetic acid and special nutrients for
the growth of acetic acid bacteria. The latter, spies of the genus
Acetobacter, are inoculated into the beech-wood shavings. The mix
is applied in a trough at the top of the chamber and allowed to trickle
down over the shavings. The mix is collected at the bottom of the
generator and is re-circulated over the shavings resulting in more
oxidation of alcohol until vinegar of the desired strength is obtained.
Oxidation of alcohol by bacteria may result in the development of
temperatures high enough top kill them. In order to keep the
temperature down to 25 to 300C, cooling coils need to be provided.
The generator method is quicker in comparison to other methods
and the vinegar may be produced within a period of 10 days. This
method is usually used to manufacture distilled vinegar. After
collection of the vinegar distillation process takes place to concentrate
Fig1: Generator for Vinegar Production (Source: www.studentsguide.in)
1) Tall oak vats are filled with vinegar-moistened beech wood
shavings, charcoal, or grape pulp. The alcohol product is poured
into the top of the vat and slowly drips down through the fillings.
2) Oxygen is allowed into the vats in two ways. One is through
bungholes that have been punched into the sides of the vats.
The second is through the perforated bottoms of the vats. An
air compressor blows air through the holes.
3) When the alcohol product reaches the bottom of the vat, usually
within in a span of several days to several weeks, it has
converted to vinegar. It is poured off from the bottom of the vat
into storage tanks. The vinegar produced in this method has
very high acetic acid content, often as high as 14%, and must
be diluted with water to bring its acetic acid content to a range
4) To produce distilled vinegar, the diluted liquid is poured into a
boiler and brought to its boiling point. A vapor rises from the
liquid and is collected in a condenser. It then cools and becomes
liquid again. This liquid is then bottled as distilled vinegar.
3.1.3. The Submerged Fermentation Method
In the submerged fermentation method a tank filled with alcohol is
pumped with oxygen and maintained at warm temperature. Primarily
used to produce wine vinegars, this process was developed in the
1950s, using tanks called acetators. The wine is kept at a temperature
between 26 and 38 degree centigrade while nutrients and air are
pumped in to the mixture. The submerged fermentation method is
commonly used in the production of wine vinegars.
Submerged vinegar systems are most commonly used by
corporations who produce high quantities of vinegar with a high
content of acetic acid. Submerged vinegar processing systems work
with the continuous aeration of the liquid. The vinegar bacteria are
floating in the liquid and do not produce a vinegar mother. Using this
system, there is no slime in the machine and the ready vinegar is
exceptionally clean and typical. Two systems are used:
work with a turbine at the bottom of the tank and bring the air into the
liquid. Those turbine machines can be controlled automatically with
an electronic system: The vinegar is pumped out of the machine
when it is ready and is then refilled with wine. These systems are
suitable for producers who plan to make more than 50,000 liters of
vinegar per year.
Venturi Air Systems
are smaller and cheaper than turbine systems. The processing is
done with a pumping system in a closed stainless steel tank. The air
is brought into the liquid with a Venturi air nozzle, which brings air
into the pumped liquid. The air bubbles have the same size like the
turbine bubbles. The processing time of venturi systems is around
30 % longer than turbine systems, but this is better for quality,
because of the lower aeration there is not so much flavor loss. As
tastings showed, vinegars from these machines are always better
The changing is done after manual controlling of acetic acid
content with a pump or with the pump inside the machine. The refilling
is done with an external pump. These machines are very competitive
and are available from 20 liters filling up to 600 liters filling. At the
moment the venturi air system is the most common processing system
for small and medium vinegar makers around the world.
1) Production plants are filled with large stainless steel tanks called
acetators. The acetators are fitted with centrifugal pumps in the
bottom that pump air bubbles into the tank in much the same
way that an aquarium pump does.
2) As the pump stirs the alcohol, acetozym nutrients are piped into
the tank. The nutrients spur the growth of Acetobacter on the
oxygen bubbles. A heater in the tank keeps the temperature
between 80 and 100°F (26-38°C).
3) Within a matter of hours, the alcohol product has been converted
into vinegar. The vinegar is piped from the acetators to a plate-
and-frame filtering machine. The stainless steel plates press
the alcohol through paper filters to remove any sediment, usually
about 3% of the total product. The sediment is flushed into a
drain while the filtered vinegar moves to the dilution station.
3.2. Quality Control
Two factors require special attention when making vinegar: oxygen
supply and temperature. Oxygen should be spread throughout the
mixture. The temperature of fermenting cider should be kept at around
In the Orleans Method, bungholes must be checked routinely to
ensure that insects have not penetrated the netting. In the generator
method, great care is taken to keep the temperature inside the tanks
in the 80-100°F range (26-38°C). Workers routinely check the
thermostats on the tanks. Because a loss of electricity could kill the
Acetobacters within seconds, many vinegar plants have backup
systems to produce electrical power in the event of a power shutdown.
Sometimes in the generator method undesirable microorganisms
might spoil the vinegar. For example the vinegar eelworm (Turbatrix
aceti) causes deterioration of flavor and appearance. Therefore, care
should be taken to check contamination by undesirable bacteria or
moulds or establishment of eelworm. The generator may be
periodically disinfected to avoid contamination.
When the vinegar is fully fermented, it should be stored in separate
containers or wooden barrels. The best place is cool (under 10°C)
and dark. Before using the vinegar, it should be cleaned by filtering.
4. Cane Vinegar Production
Cane vinegar, made from sugar cane juice, is most popular in the
Philippines, in particular, the Ilocos Region of the northern Philippines,
although it is also produced in France and the United States. It ranges
from dark yellow to golden brown in color and has a mellow flavor,
similar in some respects, to rice vinegar, though with a somewhat
Sugarcane is well known and grown widely in Ethiopia and its
juice is a good choice for natural vinegar because of its high sugar
32 BEVERAGE & FOOD WORLD NOVEMBER 2012
Fig 2: Air Lock
Cleaning (Remove trash, wash canes)
Juice extraction (crushing of sugarcane stalks)
Yeast activation ↓
Alcohol Fermentation (anaerobic)
↓← Check for the end of fermentation
Mother Liquor preparation ↓
→Acetic Fermentation ←Oxygen
Check for end of fermentation → ↓
Dilution← Quality Control
Pasteurization and Bottling
content and availability. Generally, vinegar production allows
utilization of over-riped fruits, sugarcane rejects, ethyl alcohol rejects
and cane by-products such as molasses and bagasse. In sugar
producing areas where leftover canes rejected by mills are available,
it is recommended to utilize the leftovers and produce a product such
as vinegar. It is possible to produces naturally fermented sugarcane
vinegar from sugarcane juice. Young canes may also be used for
vinegar making. If the juice extracted is below 15-16 degrees brix,
small amounts of sugar or optionally molasses may be added.
A general flow diagram for the production of sugarcane vinegar is
Cleaning step is vital to obtain a good quality cane juice. During juice
extraction focus should be given on efficiency during pressing.
Contamination should be avoided. To avoid microbial contamination
the juice should be filtered and pasteurized as soon as possible.
Then the juice should be cooled down and maintained at a suitable
temperature for yeast growth (28 – 32 oC). Saccharomyces cerevisiae
strains are used for producing alcohol. One and half gram of yeast is
added per liter of juice. The yeasts should be activated in a separate
batch so that they finish the lag phase. The activated yeasts are
then mixed with the pasteurized cane juice, allowed to multiply for 2
– 3 hours, and then kept under anaerobic condition. To create the
anaerobic environment different simple airlock designs could be
applied (Figure 2).
Figure 2 shows how CO2 gas from the fermenting tank passes
through the water filled gap to escapes in to the environment. Since
CO2 is a light gas and due to the fact that there is greater pressure in
side the tanker, it will not be difficult for the gas to boost out from the
tanker by penetrating the water filled gap. But external air will not be
capable of entering the tanker through this gap due to the presence
of water. After some time all the O2 in the tanker will be utilized by
the microbes and the environment within the tanker will be completely
To check whether the alcohol fermentation is over or not a
hydrometer is used. If no hydrometer is available, by observing the
movement of gases in the liquid one can decide to proceed to the
next step when fewer gases are produced. Filtration process is
needed to remove yeasts. The alcohol should be diluted to around
8% by volume before adding the mother liquor. Since oxygen is very
important, its supply should be monitored through out the
fermentation. Samples should be taken after wards to check the acetic
acid content at different time intervals. When the desired level of
acid is reached a final filtration is carried out; standardizing, quality
check and pasteurization bottling steps are the final steps in the
manufacturing process. Labeling is necessary.
Further Possible Improvements
Studies show that cell immobilization provides a means to improve the
fermentation process by increasing biomass, option of reusability,
protection of cells from toxic effects of low pH, temperature, and inhibitors.
Cell immobilization also helps in early clarification of the product. Further,
the choice of immobilization material in the form of inexpensive easily
available inert biological materials can help reduce the cost of the process.
A study was undertaken to develop an efficient process using
immobilized cells of Acetobacter aceti for vinegar production from cane
juice. In the study different inert materials (i.e. bagasse, corn cobs and
wood shavings) were compared for immobilization of the A. aceti cells.
First sugarcane juice was converted to ethanol by free Saccharomyces
cerevisiae producing 8% (v/v) ethanol. This ethanol was used for vinegar
production using adsorbed and entrapped cells of Acetobacter aceti.
The result of the study shows that all three adsorbed carrier materials
were statistically similar for acetic acid production and produced acidity
from 5.9 to 6.7% after 28 days of submerged fermentation. By recycling
bagasse adsorbed cells, the time of acetic acid fermentation was reduced
to 13 days. Semi-continuous fermentation of bagasse adsorbed cells
using a packed bed column further reduced the fermentation time to 80
Vinegar is the product obtained as a result of impartial oxidation of
alcohol in a fermenting sugar containing fruit or cane juice, molasses,
fermented mash of malted grain, honey, syrups, etc. Vinegar is
primarily used to flavor and preserve foods and as an ingredient in
The three common methods used for vinegar production are the
generator or trickling method, the submerged fermentation or the
Acetator method and the Orleans traditional method. The generator
method is quicker in comparison with the others. Submerged vinegar
systems are most commonly used by corporations who produce high
quantities of vinegar with a high content of acetic acid.
Generally, vinegar production allows utilization of over-riped fruits,
sugarcane rejects, ethyl alcohol rejects and cane by-products such
as molasses and bagasse. Since sugarcane is well known and grown
widely in Ethiopia, it is feasible to use cane juice as a raw material
for vinegar production. Especially in sugar producing areas, where
leftover canes rejected by mills are available, it is recommended to
utilize the leftovers for the production of vinegar.
G.S. Kocher, K.L. Kalra and R.P. Phutela (2006). Comparative Production of Sugarcane
Vinegar by Different Immobilization Techniques, Journal of Institute of Brewing.
Microsoft Encarta 2009