A good bottle of Cote du Rhone turned to vinegar
What a pity.
A bottle of wine left in the kitchen for the summer (no air-conditioning!) has turned into wine vinegar.
Besides salad dressing, what else could use a lot of it?
If the bottle was closed (and probably even if it wasn't), it's not vinegar, it's just spoiled wine. Vinegar requires a second bacterial fermentation with exposure to plenty of oxygen all the while. (Half a bottle's worth of air is definitely not enough.) There is nothing to be done with spoiled wine except pour it down the drain where it might help dislodge a little stray grease buildup.
If by some nearly true miracle you do actually have vinegar (it will have a very distinctive aroma like commercial vinegar), sauerbraten is a good way to use up a lot of red wine vinegar in one fell swoop.