Keeping a barrel

Jordan's exactly right. I make some wine at a commercial winery, and that's exactly how we treat our used barrels at the winery.

If you use any cleaning solutions like sodium percarbonate, you need to make sure to follow it up with a citric acid soaking. The citric will neutralize any remaining sanitizer and keep it out of your beer or wine.

You can store a barrel dry if you burn SO2 in it first and then keep the bung in, but make sure to give the barrel a good soak with the cleaning solution and a followup soak with citric acid before you put beer into it. You'll also want to swell it up before you put anything important in it because they loosen up when they dry out, which will cause them to leak. Filling it up and letting it rest full for a day will effectively swell it up and stop the leaking, in most cases.

Found this over at http://winebarrels.com/carenew.html

I'm pretty sure I have read similar things on homebrew forums in the past.

STORING AN EMPTY BARREL

The very best way to maintain a wine barrel is to ensure it is never empty of wine! However this is not always possible so something must be done to keep the barrel sweet.

An untreated empty barrel will quickly begin to produce moulds and bacteria. Replacing the air in the barrel with an atmosphere high in SO2 will effectively eliminate this problem.

1. Make sure the barrel is tight.
2. Rinse the barrel well and drain, bung down, for 24 hours.
3. Use one of the following methods to ensure bacteria free storage.

Method 1 - Sulphur Sticks These should be burned in a device that will collect any drips of molten sulphur. Place the stick in the burner which is suspended from the bung. Light the stick, place it in the barrel and allow it to burn completely. Re-sulphur every 6-8 weeks. Quantity: 225L Barrel approx. 1/4 - 1/3 stick 100L Barrel approx. 1/4 stick < 100 L Barrel approx. 1/8 stick

Method 2 - Sulphite Solution

1. Make up a 2% KMS solution and place a small amount (about 10% of barrel capacity) in the barrel.
2. Replace the solution every 6-8 weeks.

SOLUTIONS TABLE

Potassium Metabisulphite

• 2% Solution -- 100 gr per 4L water or 16 tsp. per 1 Imp. Gallon
• 100 ppm Solution -- 6gr per 23 L water or 1 tsp. per 5 Imp. Gallons

Sodium Percarbonate Standard Cleaning Solution

• 2/3 - 3/4 cup per full 225L barrel
• 1/3 cup - 1/2 cup per full 100L barrel
• 1/4 cup per full 46L or 50L barrel
• 1/8 cup per full 23 or 25 L barrel

Citric Acid

• 3 cups per full 225L barrel
• 1 1/2 cups per full 100L barrel
• 2/3 cup per full 46 or 50 L barrel
• 1/3 cup per full 23 or 25 L barrel