I have a problem with persistent (though slight) bubbling from several
batches of "completed" white wine. I've considered that I have
residual sugar, but they're bone dry. I've also considered incomplete
MLFs, but the wines have been well sulfited, and have been treated with
lysozyme. The clincher was when I agitated the wine and found that I
could immediately get a layer of foam. At that point, I concluded that
my problem was just dissolved CO2. Does this make sense?

At that point, I put a stirrer on a power drill and found that I could
immediately get a 3 inch layer of foam in the carboy. I let that
dissipate over about an hour, but then stirred it again and I'm still
getting layers of foam. Even just using a syringe and sucking out and
then squirting back 10 cc of wine will illicit bubbles and foaming.

So, now what do I do? Should I just keep stirring? I don't want to
bottle anything that's still bubbling, and for that matter I'm in no
rush to bottle. But just to have an occasional bubble rise to the
surface could take years for this wine to settle down. By the way, the
wine has been fined and is crystal clear, with no sediment whatsoever.
It was started about 4 months ago. These wines include
gewurtztraminer, viognier, sauvignon blanc, reisling, and pinot gris.
Same issue with all of them.

Any suggestions will be greatly appreciated.

Lee