Vinegar

I have about half dozen mini-batches of vinegar in my basement.  I'm not sure if they are "working."  I met a guy at the Reedsburg Fermentation Fest (not the last time you will hear about that...) and we exchanged some wine of mine for a double vacuum-sealed bag of concord grape vinegar with a big old chunk of mother in it.  

I put the mother in a gallon glass jug, tore off some chunks with a fork and put them into some old beer and wine to see what happens.  The picture above is some Kentucky Bourbon Barrel Porter that turned out with an ashy taste from too much black malt.  I poured 2 bottles into a glass jar and added some mother.  The first one got moldy, and I had to toss it.  With this one, I made sure to thoroughly degas the beer with repeated shaking.  The production of acetic acid is aerobic, so I figure you need to get all the CO2 out and some oxygen in.  I also gave it about 2 Tablespoons of sugar, assuming the bacteria need something to eat.

It's bubbling just a little, and the mother is floating.  I've been shaking it periodically to try and aerate it, I think that's a good idea, anyone know?  The mother keeps coming back to the top.  Vinegar is one of those things that the people who do it all the time talk about how easy it is, and I'm just not getting obvious, quick results.  I think it just takes time...