What The Cloudy Bits In Red Wine Vinegar Actually Are

Red wine vinegar is one of those pantry staples that lingers near the back of the shelf, just waiting for the right dish. Sometimes, it'll sit around for weeks or months unrefrigerated, until it's needed in your next tangy chicken marinade for tender results or it's time to make a homemade salad dressing. And while red wine vinegar technically doesn't expire, have you ever pulled out a bottle only to find it clouded with, well, something that doesn't look like red wine vinegar?

The strange substance in your bottle of red wine vinegar might be a little stringy and slimy, looking like a cross between a jellyfish and a fluffy cloud. It isn't toxic; that cloudy blob-like form floating in your bottle is called a mother of vinegar, and it's a sign that your vinegar is still fermenting.

Mother of vinegar is a jelly-like collection of bacteria that sometimes forms when drinks are fermenting, converting alcohol to acetic acid, which is what gives vinegar its taste and qualities. Red wine vinegar is just fermented red wine, made by adding the mother to any kind of regular red drinking wine. You can even transform leftover wine into red wine vinegar at home by combining it in a brand-new container with some of the mother you may have found in your old bottle of red wine vinegar. Let it sit for one or two months, and you'll have a whole new batch of tangy vinegar to use in recipes.

If your bottle of red wine vinegar has a mother floating inside, you can take a couple of different steps. Strain it out and go on using the vinegar if you don't like the look of it, or leave it in there until the vinegar is gone. Or, you could strain out the mother and use it to make another batch of vinegar. It's harmless, just part of the fermentation process that turns red wine into vinegar. And it doesn't even appear in every bottle of red wine vinegar.

A gelatinous mass of mother can form in red wine vinegar if it's exposed to oxygen, or if there is sugar or alcohol still present in the liquid for it to ferment. It grows larger and larger over time and is usually filtered out in commercially produced red wine vinegar. The commercially produced variety is usually pasteurized as well, which will kill off the bacteria that produces a mother. That means many brands of red wine vinegar would have to be inoculated with mother of vinegar to produce a mother at all. So, you can consider yourself lucky if you find a mother in your red wine vinegar, whether you decide to throw it away or use it to start your own batch.