Q: I just made my first batch of wine with the help of a friend who has been making wine for several years. We used frozen raspberries and sanitized everything. later, When I bottled I got a hint of vinegar and was hoping the sample taste was in my head and not for real. Tonight, on opening our first bottle, my husband said, “I taste vinegar!” That then confirmed my awful thoughts. Is there anything that I can do to salvage my first attempt at winemaking or should I just pour it all out?
— Lori Washington • Wilmington, Delaware

A: The quick and dirty answer to your question, and quite possibly not the one you want to hear, is that you’re best off dumping your vinegar bottles of wine down the drain. Once your wine has been infected with vinegar-causing bacteria, Acetobacter, there is nothing you can feasibly do to remove or reduce the vinegar content in your wine. 

Big commercial wineries can take advantage of reverse osmosis technology and remove their acetic acid, still a relatively expensive and rare “salvage” maneuver. Unfortunately, home winemakers don’t have the volume (or the thousands of dollars) to justify such treatments, nor is there the equipment small enough to run home winemaker-sized batches. At the end of the day, home winemakers are better off concentrating on preventing, rather than curing, high acetic acid (the main ingredient in vinegar) levels. 

Acetobacter are ubiquitous in our general environment — in fact, you’re probably breathing some in right now. Since they’re so ever-present, we will never be able to completely exclude them from the winemaking environment. All we can do is try to restrict their access to the things they need to thrive and multiply: Oxygen, a happy environment, and a food source. To try to reduce the chances that Acetobacter will infect future batches, keep the following in mind:

Keep pH as low as possible and acid as high as possible, within intelligent style limits. Bacteria are repressed by higher acidity and thrive in high-pH environments. I like red wines to finish MLF (malolactic fermentation) at a pH no higher than 3.75. 

If there is headspace in your bulk storage containers (barrels, carboys, kegs, etc.), blanket the surface with carbon dioxide or argon. These gases are heavier than air and can help exclude oxygen from the surface of the wine. Keeping containers topped and completely full is one of the most important things you can do. 

Clean and sanitize all winemaking equipment before it touches your wine.

Be especially vigilant with finished wines. These wines don’t have the natural protection that carbon dioxide gas provides to fermenting wines and so are especially vulnerable to the effects of poor sanitation, oxygen ingress, and exposure to environmental microbes. 

Use adequate sulfur dioxide during all stages of a wine’s life. This is one of the biggest blunders I see new winemakers make. Finished wines need to be stored at 20–35 mg/L free SO₂ (low-pH wines closer to 20, higher-pH wines closer to 35) and bottled with about the same amount. 

If you don’t want to dump this batch out, you could always try to turn it into a delicious homemade vinegar (raspberry vinegar is amazing!). Check out this article on making wine vinegar we ran in a past issue at: www.winemakermag.com/article/make-vinegar

Remember that an ounce of prevention is worth a pound of cure — and maybe you can salvage some good homemade gifts of raspberry vinegar out of your first attempt at wine.