by Tim Hall on Wed Aug 06, 2008 2:40 pm
Once you've got vinegar, I'm pretty sure that's just what you got. I don't think I've ever heard of anyone overcoming an Acetobacter infection by pitching fresh yeast, and the flavor is not likely to age out. But on the bright side, the best vinegar I've ever had was from a batch of mead that didn't work out quite as planned.
The "rubbing-alcohol" character you're describing could be several things...maybe esters or other alcohols that will most likely mellow with age. It could also be ethyl acetate, which might indicate it's beginning to turn to vinegar also. You will probably just have to wait and see.
In the mean time be sure your fermenting vessels have a good airlock on them. It sounds like a little too much oxygen may have gotten to your brew. Also be sure to clean your vessels and utensils thoroughly before your next batch, unless you want to start with vinegar right away.
Am I answering too many of the questions here?
Edit: it is also possible that you have a LAB "infection." If your brew tastes sour, but doesn't smell of vinegar (you said it "tastes" of vinegar), it could be lactic acid from Lactobacilli. In which case you might chill it, sweeten it with some honey, and serve like spiked lemonade.