If you've added too much vinegar to a recipe, there are a few things you can do to try and salvage it. First, if the dish is savory, try adding some more of the other ingredients to help balance out the acidity. This might include adding more salt, fat, or sweetness. If the dish is sweet, you can try boiling off some of the vinegar or masking the flavor with other strong flavors like chocolate or coffee. Finally, if all else fails, sometimes you just have to start over!