I didn't realize there was mold on the top and bottom of my white wine vinegar until I had added a teaspoon into the ingredients for Tzatziki. Is it OK to use or should it be discarded?
It depends; if it's formed a solid disk and was/is floating on top, what you probably have is a vinegar mother, not mold. It's a bacterial colony of acetobacter, and probably happened because your vinegar still had a little bit of alcohol left in it for the bacteria to feed on.
You have several options if this is the case:
- You can leave it in the bottle; it will do you no harm.
- You can filter it out with a coffee filter or similar and discard it. Your vinegar will be fine.
- You can put it in a bottle with (perhaps not so great) wine and/or the leftovers of bottles and make vinegar.