Whiskey Barrel Sanitation

[haslips]

Long time lurker....first time poster here.

This past fall, I recently purchased a "Just emptied" whiskey barrel. I coordinated a Collaborative with 5 other home brewers and we developed a cream porter all-grain recipe. We each then brewed and fermented the beer, racked to secondary, then a week later racked all 50 gallons to the barrel to blend and age. The night before I filled the barrel with a light ratio of potassium metabisulfite and water, then drained the morning of the fill. Since the barrel was new, we decided on a Thief party two weeks into aging. This turned out to be perfect as the bourbon hint was as we called it "Goldilocks"....
So, my question to the forum.... We'd like to do another collaborative.....maybe an IPA next.....and since we've already pulled some of the "Taste" from the barrel, I suspect a longer age is necessary to get the flavor we want. In the interim, how do I keep the barrel clean and sanitised? We rinsed the barrel with water and starsan after we transfered the cream porter out, and recapped the bunghole. My concern is now, instead of whiskey inside the barrel, I now have water that could cause problems. It will be weeks or even months before we are ready to transfer the next 50 gallons into the barrel for aging.
Thanks in advance for any recomendations/input.
Regards
Kilkee Brewing

 

[dstar26t]

When I empty a barrel of beer, multiple hot water rinses (170-180F) are used by way of a pump and spray ball. Don't use starsan.

If you're storing it for a while, there are 3 techniques you can use:

1. The wine industry uses sulfur bungs but I'm not sure when you can use one on a used spirit barrel with respect to residual alcohol left in the wood and a possible explosion. Definitely not with a freshly dumped barrel but maybe after one or two beer uses? Not sure. Make sure to follow the proper procedures if going this route.

2. You can pour a gallon of spirit into the barrel to keep it sanitary and wet inside but you'll have to move the barrel around periodically to keep all surfaces wet and in contact with the spirit.

3. Fill the barrel with a holding solution of 5.25g Citric acid and 11.25 grams K-meta per gallon of water. Fill it all the way and top off as it evaporates every few weeks. This technique will leech oak and spirit flavor out of the barrel which could be a good or bad thing depending on what you're looking for.