One way to ensure we’ve got high-quality vinegars is to make and age them ourselves. The DIY approach requires very little effort and saves money, as good vinegars are pricey.
The word vinegar comes from the old French vin egre meaning “sour wine.” In Wild Fermentation, author and fermentation expert Sandor Katz writes that his experience with vinegar-making began as winemaking gone awry. “Vinegar is an excellent consolation for your winemaking failure,” he writes.
Any liquid with fermentable sugars or alcohol in it can be turned into vinegar. Wine makes wine vinegar, cider makes cider vinegar and beer makes malt vinegar. When alcohol is exposed to oxygen, it is transformed by oxygen-loving acetobacter bacteria into acetic acid, more commonly known as vinegar. The ubiquitous acetobacter in the air find the alcohol in loosely covered wine, cider or beer and go to work. Katz says the simplest method — albeit sometimes faulty — to make alcohol and vinegar is to let unpasteurized apple cider sit for a week until it becomes alcoholic, and then let it sit for another couple of weeks until it becomes vinegar.
To ensure your fermentation creates flavorful vinegar, however, it’s best to use a starter, also called a “mother of vinegar.” The mother is a gelatinous mass of vinegar-making organisms that forms naturally in vinegar. You can order a starter that will clump together and form a mother during fermentation. Add the starter (or mother) to a new batch of alcohol — wine, cider or beer — and leave it there until the vinegar tastes right to you, at which point you may remove the mother and use it for a new batch.
1. Gather Your Vessel. Use a wide-mouth crock, glass jar, food-grade plastic bucket, wooden cask or other non-metal container (vinegar corrodes metal). Don’t fill the container more than half-full, to maximize the surface area ratio.
2. Gather Your Starter. You can get a mother of vinegar from wine and beer supply shops or online from Etsy. You can also borrow a starter from a bottle of store-bought vinegar that contains the mother, such as Bragg organic apple cider vinegar.
3. Gather Your Ingredients. To make wine vinegar, you want 1 part starter (or mother), 1 part unchlorinated water and 2 parts alcohol. Use unsulfited organic alcohol if possible, as sulfites kill acetobacter bacteria. If your wine contains sulfites, let the mixture sit for a half-hour before covering. If your water is chlorinated, boil it and let it cool, or let the water sit on the counter overnight. For cider and beer vinegars, omit the water. Add alcohol and water, if using, to your vessel. Stir. Gently add the mother.
4. Cover The Top. Place cloth or a few layers of cheesecloth over the container and secure with a rubber band.
5. Store The Vessel. Set the vinegar pot where temperatures stay between 65 and 90 degrees, out of sun and drafts.
6. Monitor The Vinegar. Over time, the mother on top of the vinegar will become thicker. It may develop a brownish cast, which is fine. If you see mold or smell a paint-thinner aroma, toss the batch. (This is rare.)
7. Taste. After a couple of weeks, sample a spoonful of the vinegar. Simply remove or lift the mother out of the way. It’s OK if the mother sinks. If the liquid tastes like vinegar, it’s ready. You may want to leave it to ferment longer for a stronger flavor. In warm temperatures, vinegar may be finished in two weeks. In cold temperatures, it may take a month or more — it’s OK to let it go longer. Vinegar is stable for a long time, though it will begin to lose its potency in time.
8. Draw Off Finished Vinegar. Pour the liquid through a strainer. Decant almost all of it to a clean glass jar with a narrow neck and a top with a tight-fitting lid or new cork to reduce further oxidation. The vinegar will continue to age and mellow in the bottle.
9. Save The Mother. Put the mother back into the fermenting vessel and pour remaining vinegar over it. This is the mother of vinegar for your next batch. You can either start a new batch now or let your mother sit at room temperature for up to a month until you’re ready to use it again. If you plan to share the mother, now is the time to split it.
10. Age The Vinegar. Store vinegar at 50 to 60 degrees for six months to mellow. Vinegar will improve for up to two years, then slowly decline. Use the vinegar as is, dilute it, or infuse it with herbs or spices.
For more helpful tips about vinegar visit: How to Spot Healthful Vinegar