What wine are you putting in these barrels? When was it made? How has it been stored prior to introducing it into the barrels?
The wine I put in those barrels is a Chilean Rapel Casa Rosa blend (Merlot/Syrah/Cab.Sauv) made from juice buckets this spring. It was stored in 6 gal glass carboys until I transferred it into the barrels. I checked it every month for SO2 and tasted it along the way and it was OK. I added tannin to it a couple of times and did a small acid adjustment in the summer, with tartaric acid.
I don't know how and why the wine in that barrel got to this point, that's why I asked the question in this forum. I was hoping that maybe someone with more experience could shine some light on the issue.
I don't have any prior experience with barrels and I need to understand what happened before I feel comfortable putting another wine in that barrel. I'm also looking for some guidance on what to do.
Did you follow the Vadai preparation instructions? They include filling the barrels with nearly boiling water on the outside heads as well as the inside. This activity would certainly reduce any concerns about the barrels coming infected. That, coupled with your sulfite / citric acid solution, and high sulfite content in your wine should alleviate infection as an issue.
I did the barrel preparation as described in the instructions that came with the barrels. The only deviation was the sodium carbonate test, but I did that on the barrel that's still OK.
I used the silicone bungs from More Wine that they recommend for these barrels, not the wooden bungs from Vadai. I keep the barrels in my finished basement, which is very dry because I have to run a dehumidifier down there year round. I keep the barrels on stands that I mounted on furniture dollies for added mobility. They are sitting 8" above the basement floor.
As far as oak taste, I don't like my wines very oak-y. I understand others don't mind strong oak taste and smell in their wine, but I like a light level of oak and that's what I'm going by. That was the reason why I wanted to test the fast neutralization of the barrel in the first place.
Tonight I'll rack the other barrel into a glass carboy and store both barrels with citric/k-meta until I can figure out what happened. I keep thinking about it and the only thing I can maybe point a finger at is that the barrel with the oxidized wine had a small leak at the top (between two staves, near the bung hole) that only showed up after I put wine in the barrel. It was not there when I had water in it. The wine seeped through that small hole for 3-4 days until it stopped and I thought the issue was resolved.
Does anyone have any recommendations on what I should do at this point? Is there a test to check for Acetobacter, or a way to get rid of it, if that's the case?