Ever wondered how to create your own vinegar? This article is an introduction to how vinegar is made, and a guide on how to make your own.

The Submerged Fermentation Method

Used most commonly with the creation of wine vinegars, a steel tank of wine is kept at a temperature between room and body temperature (roughly 26- 38 degrees celcius). Nutrients added to the mixture encourage the growth of acetobacters which speed up the change from wine to vinegar. Water is used to dilute the vinegar to the right acidity.

The Trickling / Generator Method

Alcohol is trickled slowly down from a vat made of stainless steel or wood, through wood shavings soaked in vinegar. The increased surface area on these wood shavings develop bacterial colonies, which speed up the chemical change. On the sides and base of the vat, oxygen is blown through to aerate the liquid and speed up the process.

The Orleanais Method

This method of producing vinegar is widely recognised as the way to achieve a perfect vinegar. The wine is put in a wooden barrel, with holes drilled just above the level of the vinegar and on the lid of the barrel. Through these holes (covered to prevent insects from contaminating the contents) mother of vinegar is added, which sits on top of the alcohol. After months, the alcohol turns to vinegar, and to perfect the flavour, the vinegar is often stored in a second similar barrel until developed fully, which can be over half a year.

If these methods seem at all complex or off-putting, then it's assuring to know that you don't need the skills of an expert to make your own. These instructions will guide you through the process, from mixing to bottling.

To start the process, a mother of vinegar is needed. This is a culture created from acetic acid bacteria (acetobacters) and yeast. This culture is vital to aid the fermentation process. To make this culture, pour 500 ml vinegar and 500 ml wine, cider or fruit juice into a medium to large sized jar. If you use fruit juice, it is important to make sure that it is organic and unfiltered, as chemical traces can inhibit the growth of the culture. Instead of lidding the jar, secure a cheesecloth (or similar porous material) over the top to keep out bugs. The jar should then be stored in a warm place such as an airing cupboard for roughly two weeks.

After this time, there should have appeared on the surface of the liquid, a jelly-like layer which is the mother of vinegar. This layer must be handle carefully when transferred to the next stage of the process. Pour into a second jar four times as much wine/organic juice as you have mother of vinegar, and transfer the mother of vinegar carefully so that it floats of the top of the liquid as it did before. If the culture sinks, then it is unable to process the vinegar because it will be starved of oxygen.

This second jar should be stored in the same warm dark conditions, covered by a cheesecloth for a month. Over this time, periodically taste the vinegar to see how the flavour matures over time, being careful not to introduce new cultures on licked spoons etc. The vinegar can be left as long as desired, and the flavour will only improve.

When you are happy with your results, the vinegar needs to be kept in a sterile glass container and corked (do not use containers with metal lids at any point, as the acid from the vingar can corrode it). Use a paper filter to remove any culture.

Next, you will need to work out the acidity level of your vinegar. If your vinegar is too strong, it will be unfit to use in cooking. There are many ways that you can test the pH of your vinegar. If you are pressed for time, then a pH tester included in a titration kit (from a wine-making supplier) can be used. Otherwise, creating your own indicator with cabbage water and baking soda is easy.

To make your indicator, boil up 250 g red cabbage in water, which will turn deep purple. When you have removed the cabbage and put aside the water, add two teaspoons of baking soda to a glass of water and dissolve.

Fill a second and third glass with water, labelling one 'control' and the other 'experiment'. Add two tablespoons of cabbage to each glass. To the control glass, add 10 drops of a shop bought variety of plain white vinegar (with an acidity level of five percent - the target level for your vinegar) and then 20 drops of the baking soda water. When stirred, the mixture should turn blue.

Now add seven drops of your own vinegar to the glass labelled 'experiment', then carefully add drops of the baking soda water, counting each drop. Continue until the liquid in the glass is the same shade of blue as the liquid in the 'control' glass. If each glass has the same shade of blue, then they are both the same pH.

You can now calculate the pH of your vinegar by dividing the number of soda water drops added to the experiment glass by four. Often the vinegar will still need to be diluted before it can be put on the shelf.

If things aren't going to plan, have a look at some of these pointers.

The vinegar mixture isn't doing anything

This may be because the growth of the bacteria is being inhibited by sulphites or other preservatives which have been added to the fruit juice or wine that you have been using. It is possible to dilute sulphites with water, but if this doesn't work, then restart the process with a different wine or juice.

If your vinegar still does nothing when using organic preservative free wine or juice, then this may be because the culture has sunk down the jar. If this has happened, introduce more alcohol to the mix and it may rise back to the top. If not, restart the process.

The vinegar is too weak

Too much water may be in your solution, causing the vinegar to have a diluted taste. Or the acetic acid may have been converted to carbonic acid and water. To improve the vinegar's strength, add more alcohol to the mix.

The vinegar smells 'off'

The vinegar may smell 'off' in the first month while it is still maturing. If the vinegar still smells strange after a month, this could be resulted from a lack of oxygen. Check that the cloth you have place over the top of the jar is porous enough to let oxygen through. There may be not enough air movement where you are storing your jar. Try pouring the vinegar (taking care to keep the culture on top) into a new jar twice in a single day to increase its oxygen exposure, and then leave it for a week.