Well, I was having trouble getting a vinegar going, since I was using a wine that had a rather high ABV for vinegar making (12% or so) So, to compensate and not lose the starter culture, I basically dumped a lttle less than half out, replaced it with water that had been boiled and cooled to remove chlorine, and waited. Now I'm seeing particulate gathering near the top of the matter, which I would assume is the formation of a mother. However, I'm also seeing something I did not expect, bubbling similar to the initial yeast fermentation. Does the acetobacter also produce a gasous excrement? I actually heat pastuerized the initial wine since I wanted to use it for vinegar, so I was thinking that after diluting, the mix would have a low enough ABV to become host to wild yeasts in the air. There might have been some residual sugars left in there, but the champaign yeast really should have rifled through all of it in two weeks though (it was only a pound of sugar for a gallon, with pretty moderate yeast activity). Is mild bubbling normal for acetobacterial fementation?