Wine vinegars, whether red or white, are a ubiquitous ingredient in salad dressings, sauces, stews, and slow-roasted dishes. And, it is easy enough to pick up a bottle at your supermarket, but, as with most food products, a homemade version tastes better than a mass-produced, store-bought. Homemade wine vinegar will be stronger and more concentrated, with a more delicate, but complex flavor. This will not only improve the taste of your recipes, but homemade wine vinegar also makes a nice gift.
And it's quite simple to make. (You may have even accidentally made wine vinegar in the past by leaving out an opened bottle of wine too long!) To start, you will need a good-quality wine (red or white) that's not too strong (about 10 to 11 percent ABV); too much alcohol inhibits the activity of the bacteria that transform the wine into vinegar. On the other hand, if the alcohol content is too low, the vinegar won't keep well. Depending on how much wine vinegar you'd like to make will determine the method you use.
Make 1 Bottle
The easiest way to make your own wine vinegar is to leave an open, 3/4-full bottle of wine in a warm place for a couple of weeks. It's really that simple—the natural oxidation process will do all of the work. The only issue you may encounter is fruit flies. To avoid this, place a small piece of cheesecloth over the opening of the bottle.
Make a Steady Supply
To make larger amounts of wine vinegar you will need what is called a "mother" vinegar. This fermenting bacteria culture turns alcohol into acetic acid (in combination with oxygen) and can be purchased as "live" or "mother" vinegar or simply as an unpasteurized vinegar. You can also make your own mother vinegar by combining wine and vinegar and leaving it to ferment.
For a constant supply of vinegar, pour 1 quart (4 cups) of wine and 1 cup of the mother vinegar into a wide-mouthed glass jug with at least 1-gallon capacity. Cover the container with a piece of cheesecloth secured with a rubber band. In a couple of weeks, the live vinegar will have settled to the bottom of the jug, while the vinegar above it will be ready for use. Add more wine as you remove vinegar for use, to keep the level in the jug constant.
Make Large Batches
If you want to make wine vinegar in larger batches, you will need a 1-gallon glass or ceramic cask that has a spigot at one end. If it's new, rinse it with vinegar and let it dry. Next, fill it to within a couple of inches of the top with wine and place it, covered with cheesecloth, in a location that's about 68 F (20 C). In a couple of weeks, the wine will be vinegar. Drain it from the cask using the spigot. Replace the vinegar used with more wine, adding it into the cask through a hose or a funnel, so as to leave the mother undisturbed.