I have a one-gallon oak keg that I use to experiment with oaking. A week
ago, I filled it with a gallon of Isaac, my grape-elderberry blend, and put
it up on a high shelf in the wine cellar, temporarily. Out of sight, out of
mind; I forgot about it and it seems that condensation from a pipe dripped
on it. The outside of the barrel had parts which were covered with a fine
white mold, like a thin beard.

I brushed off the mold and poured a sulfite solution over the barrel to soak
it down, in hopes of preventing whatever was growing on the outside from
getting inside. The wine still smells and tastes ok. Hopefully I caught it
in time.

Has anyone ever had a similar experience?

Paul