One of life’s greatest displeasures is opening a bottle of wine to drink only to have part of the bottle left over, unfinished and past its prime a few days later. With every drop that gets reluctantly poured down the drain, you wish you’d either had help in polishing off the bottle or some way of preserving it.
There’s a way, however, to let the wine not go to waste completely. Making vinegar with your spent wine, although it takes a little more effort than a swift pour down the drain, is a creative way to let your old wine have a second life.
What Is Vinegar?
“In my simplified terms, vinegar is an acetic acid fermentation that’s made by converting alcohol to acetic acid through lots of free oxygen and bacteria, most commonly acetobacter aceti [a specific genus of acetic acid bacteria (AAB)], which exists in the air around us all across the globe,” says Jori Jayne Emde, the founder of Lady Jayne’s Alchemy and fermentation consultant for Fish & Game in Hudson, N.Y.
This type of acidity is one of the most common ways chefs liven up their dishes, and it’s also a form of fruity acidity that bartenders employ for balancing cocktails as well (usually in the form of shrubs). Historically, dating all the way back to 6000 B.C., vinegars were made from wines, but it’s now also possible to make vinegars from spirits, ciders, grains, fruits and vegetables using various techniques.
Where to Start
Once you decide to try your hand at this simple method of fermentation, it’s time to first do some light reading. “I would recommend [enthusiasts] read and understand what vinegar is first, so they can understand what’s happening in their fermentation experiment,” says Emde. “Many people these days jump to a project without completely knowing what's actually going on, and then there’s a lack of confidence with their projects.”
There are a few ways you can turn your spent wines into vinegar, and it’s important to choose which method is best for you. “You can allow your wines to oxidize/acidify [become more acidic] spontaneously, but that can be a little haphazard,” says Johnny Drain, a renowned fermentation expert and consultant, who runs fermentation research and development for Cub in London. “And it's slower,” he adds. By “slower” he means the process can take months to be completed. “For more control and consistency, you want to enlist the help of microbial collaborators: acetic acid bacteria,” he says. This bacteria can be added in either of two forms to your spent wine: by adding unpasteurized vinegar (either unpasteurized apple cider vinegar or an unpasteurized vinegar from a previous vinegar batch, sourced perhaps from a friend or online) or a vinegar starter (i.e., a zoogleal mat, or a gelatinous blob of AAB).
Making the Vinegar
It’s important to understand how the wine you’re using will determine the type of vinegar it’s likely to yield. “The higher the sugars and alcohol, the higher the acetic acid will be in your vinegar, so if you want a nice sharp wine vinegar for pickling or condiments, then a high-sugar wine like a riesling is great,” says Emde. “If you want a lower-acid vinegar, for drinking or for shrubs, then lower-alcohol wines or beer or cider are better.” If your wine is higher-ABV, then you can dilute it with water to a lower alcohol percentage, but it’s recommended that you follow a specific recipe for this.
These are instructions for exactly how to use your spent wines and turn them into something equally delicious. (Note: While these recipes use tools and specific measurements for the optimal results and for accuracy and consistency, it’s still possible to create vinegar from your spent wine without this degree of precision, as long as you add any source of AAB to it and cover your vessel of choice with cheesecloth so your ferment can receive the oxygen it needs.)
Jori Jayne Emde’s Instructions for Making Red Wine Vinegar
- Place a quart-size jar on a scale and tare to zero.
- Pour red wine (up to one bottle) into the jar and note the weight.
- Divide weight by four and add that quantity of any unpasteurized vinegar to the jar. (For example, if you have 550 grams of red wine, add 137.5 grams of raw vinegar.)
- Cover the jar with cheesecloth and keep at room temperature out of direct sunlight. Stir the mixture once a week. You want the liquid on the bottom to make its way to the top of the jar to be exposed to free oxygen.
- Allow the mix to ferment until it smells sharp and vinegar-like. Once it does, check the pH with a digital pH meter. The pH should be between 2.5 and 5. (The lower the pH, the stronger the acid.) Once you’ve achieved the desired acidity, fine-strain the mixture into an airtight container and store it at room temperature out of direct sunlight.
Johnny Drain’s Instructions for Making Old Wine Vinegar
- Take a bottle of wine and decant into an open-necked vessel (such as a mason jar).
- Dilute it as needed to 8% ABV. (This requires some math. For example, if you’re using 750 mL of 14% ABV wine, you would need to dilute it with 560 mL of water.) Leave about 30 cm of headspace at the top of your vessel, as the wine may foam when you bubble air through it.
- Add your source of acetic acid bacteria to the wine (unpasteurized apple cider vinegar or vinegar starter). The optimal mix is vinegar starter plus unpasteurized vinegar, the latter at a quantity of about 20% of the volume of the diluted wine. If you use only the starter, that's fine; the process will simply take a little longer.
- Cover the top of your vessel with cheesecloth to let air in and out but keep any pests out. Then let it stand, bubbling, for about 10 to 20 days.
- The surface of the liquid should get covered by a gelatinous vinegar mother, which you can see clearly if you’re using a clear-sided glass jar. (It won’t look pretty, but that's normal.) Measure the pH to tell when it's done (aim for a pH of 2.4 to 4.4) or simply taste it.
- When you've hit your target pH, or when it tastes good to you, strain the mother off and save it for your next batch. Filter the vinegar if you want it to be clearer and bottle it. If you don't pasteurize your vinegar, you may get a wee mother growing in the top of your storage bottle; that's normal too.