Vinegar?

Have any of you made vinegar on purpose or on accident? I need some advice on storage and clean up.

The back story is: I was just getting ready to bottle my second batch of hard apple cider. The first batch from mid July is back sweetened and carbed up. My wife loves it. So right away I got some more apple juice and put it on the yeast cake from the 1st batch (Wy 1056). I checked it on 4 days ago. The Kueusen had fallen and there was a wonderful apple aroma. Ready to bottle...Well today it is very sour smelling and tasting. The SG is down to 0.998. Which is 4 points lower than the "successful" 1st batch. I just sampled a bottle from the 1st batch, no off flavors.

So my question what do I need to do to keep these "bugs" away from the rest of my beer? I hate loosing 5 gallons of cider but if this is really vinegar I guess I can always use it for BBQ marinade. I am thinking of moving the bucket of apple vinegar out of the basement to the "hot" garage to see what happens. Buckets are cheap so I'm trashing this one. I have not used any of my other beer equipment to transfer/rack any of this infected apple juice. How do you store vinegar? Should I try pasteurizing it because it will continue to ferment the ETOH? What do I do to keep the rest of my fermenting beer from being exposed? Millions of questions...Help! Any advice would be helpful.

Move it to another room ASAP then sterilise anything that has come into contact with it. It doesn't really sound like you have vinegar, just young cider, especially if you're trying it as soon as the krausen had fallen. It's not unusual for ciders to ferment lower than 0.998. I don't know the answers for your other questions but good luck!

I would be willing to guess that it's not infected with aceterobacter (the bacteria that cause vinegar). It sounds like you've simply got some young cider that is almost done fermenting. It's not unusual for ciders to finish dry, at .990, so it's not usually considered "done" at 1.000. I wouldn't move it to a hot place, but instead let it finish up right where it us.