Though most of us like to keep a well-stocked pantry at home, there are definitely occasions when we have red wine vinegar or white wine vinegar but not both.
We wondered if we could distinguish between the two in a salad dressing once it was tossed with the greens. To find out, we made batches of vinaigrette using our favorite red wine and white wine vinegars. We dressed mild Bibb lettuce with each and asked tasters whether they could determine which was which and if either was unacceptable.
Some could tell the two dressings apart, but most could not. Those who did notice a difference found the dressing made with white wine vinegar to be brighter in flavor. But none considered either vinegar to be unacceptable, despite the difference.
The takeaway? If a dressing calls for red wine vinegar and you have only white (or vice versa), just use what you have.