Balsamic vinegar takes time, as in more than a decade, minimum. The technique itself is simple and hardly differs from making regular red wine vinegar -- until you get to aging. Genuine balsamic vinegar, or aceto balsamico tradizionale, undergoes at least 12 years of oak-barrel aging to impart vanilla, cherry and oak flavors that make it grand. The timely option for making balsamic vinegar, one you don't have to wait until retirement age to enjoy, is balsamic vinegar of Modena, a commercial grade of balsamic vinegar made by caramelizing red wine vinegar and aging it for two months.
Dilute the wine with a wine-bottle full of distilled water. Vinegar bacteria won't metabolize in wines with 12 percent or high alcohol content.
Add the mother of vinegar, which will be a cloudy white clump of cellulose, to a purpose-made crock with a spigot at the bottom. Pour in the wine.
Cover the wine with three layers of cheesecloth. Secure the cheese cloth to the vinegar crock with a rubber band or kitchen string.
Set the vinegar crock in a room with a temperature between 60 and 80 degrees Fahrenheit. The room needs to be dark. A basement or attic works, but so does a closet. You can also place the crock in a cardboard box and place it in a room that stays within the desired temperature range.
Let the bacteria work on the wine for three months. You will know the wine has turned by its smell.
Transfer the vinegar to another container. Discard the mother of vinegar. Strain the vinegar through a sieve lined with a few layers of cheesecloth.
Strain the vinegar again, this time through a sieve lined with a coffee filter. This removes fine sediment.
Transfer the vinegar to a stainless-steel saucepan. Add 2 1/2 cups of sugar to the vinegar.
Simmer the vinegar until it reduces by half in volume. Transfer the vinegar to a sanitized 1-gallon glass jar.
Cover the glass jar with three layers of cheesecloth. Place the vinegar in the dark room to age for at least two months. The longer you age the vinegar, the more complex its flavor. You can age the vinegar indefinitely, but try it after two months and determine if it needs more time according to your tastes.