I am the proud owner of a used 55 gallon oak barrel (formerly Heaven Hill bourbon, then used once for a commercial beer).
After using for the commercial beer, the bung was not replaced, and it was rolled outside. I do not know how long it was outside, but would guess less than a week. It was fairly cold (not above 40, I believe) for the time it was outside. It still smells like beer and bourbon (no off smells that I can tell).
The ends (top and bottom) are warped. I am not sure if this is normal, or due to being outside with melting snow on it.
If I were to use this for aging some imperial stout, what are my options? Should I re-sanitize (sulfur stick? sodium metabisulfite and citric acid? something else?)? Should I dump in some fresh bourbon/whiskey/whisky, let it soak in a bit, and fill with beer? Should I pop an end off and re-char the inside? Or should I just consider it no longer useful for beer aging, and convert it to a portable (with enough strong individuals) keg dispensing system?
I tried searching for previous discussions of this, but had a hard time finding anything, so bear with me, or point me to another thread where this was discussed.