For those who have made their own vinegar, or have bought some they want to age and refine, aging vinegar is the easy part though patience is a must. Vinegar can age almost indefinitely if stored right. Traditional Chinese vinegars are aged 3-6 years, traditional Balsamic is aged from 12-25 years and sherry vinegar can be aged for similar long periods before bottling.
During aging, a lot of complex chemistry goes down. One of the most important reactions is the slow reaction of acetic acid (as well as other acids) and alcohol to make esters which impart flavor to the vinegar. To do aging right, remember a couple of key rules:
- Age the vinegar in a sealed container that the vinegar can fill as completely as possible. You want minimal airspace. Airtight containers or wooden barrels are a near must though barrels need to be filled completely with no surface area for an additional mother to grow and carry on more fermentation.
- Use additives or flavor enhancers sparingly. For example, if you want to add herbs or spices to age in the vinegar, you don’t need a huge amount. A couple of sprigs of thyme or a tablespoon of dried herbs/spices can go a long way in one gallon of vinegar if you allow it to age for months. For oak chips or cubes, use the amount on the package for a similar volume of wine. Boil a couple of minutes before adding to remove harsh tannins. You may want to remove the chips or cubes after a while if you think the oak flavor is heavy enough so sample it every week or so. You can continue aging without them.
- Make sure you age enough vinegar to both use and age. If you consume an aged barrel of vinegar in 2 months but age the vinegar for six months, you need 3 barrels aging at any given time, preferably separated by 2 month intervals. This also assumes you are fermenting new vinegar every two months. In general, the amount of vinegar you use in the time new vinegar is aging is how much you need to have aging continuously to not run out.