Cleaning a old oak barrel

[nvs-brew]

Picked up a 25l old and in bad condition barrel..
It was all shrunk and been left dry for god knows how long..
I filled it with water and got it water tight, then kept water in it for a couple of months..
Just emptied it out and a lot of the gunk and crap came out.
Roy from TWOC said to fill it with water/sodium metabisulphite..
Now how long would you recommend leaving it in there? Till I'm ready to fill it?
I've been trying to get info from google on my phone and its not very helpful..
Google said up to 6 months.. And also said use some citric acid.. I only had some lime so added that..
I'm not confident.. Bloody google

 

[jordanelwell]

Have just found this thread while looking for an answer to a similar question. Did you ever find a good solution? No pun intended

 

[BrewerBrad82]

Old barrels can be horribly problematic. If it was in disrepair I applaud you for getting it to swell back up enough to seal. The issue with old barrels is that they can be laden with funk. Sachro, Brett, bacteria, lacto, ect can get itself so far into the wood that it is nearly impossible to get the barrel clean again. Your best bet (as already been done) is to do a nice long soak with potassium metabisulfite and citric acid. The citric acid will lower the pH of the overall solution, making more free SO2 (sulfur dioxide) available. This will go a long way in killing off any nasties in there. Your next line of defense is to empty the barrel and burn a sulfur strip in there. Use caution with this approach if the barrel was previously used for spirits. (Gordon Strong tells a cautionary tale about that subject). Even then, the funk may have gotten so deep into the wood that is essentially impossible to get them out.