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Jun 08, 2022 View:

Barrel Leak-Check Water

Hello All,

When you test the seal of your barrels, what type of water do you use? Would tap water suffice, or do you want to use filtered or even RO water? I'm thinking tap water might leave residual contaminates that would find their way into the whiskey.

Note: We are using full char, american white oak barrels, for whiskey.

Thanks for your thoughts and advice!



Sorry - first post in the forums and I appear to have misplaced it - this should probably be in the whiskey specific forum. Apologies.


We rehydrate the barrels and check for leaks using filtered water (no chlorine).


Shouldn't need any special water, so long as your tap water isn't overtly hard, salty or chlorinated. Hot water is best. New barrels just need a few gallons of hot on the inside of each head, to swell. (So long as the barrel isn't "loose") Older barrels, just filling with clean hot water should do the trick. If you're in an area with oak bore beetles, square-round toothpicks do the job in patching up any holes. Good luck


Steam also works well. If you have a steam tap off of your boiler header, you can put a steam-rated hose inside the barrel, let it sweat for a few minutes, rinse with clean water, dump the barrel dry, and you're good to go.




Good call, John. Steam is an excellent cleaner/hydrator. And you rinse out minimal barrel character


We are filling up the heads of our barrels with filtered water and when they hold we flip em and do the other side. When that holds we load em up with spirit. I forget who taught us that but it works like a champ. Anyone else doing this?



Thats the usual recommended MO for most cooperages, i think.

Edit: I realize you might have meant the outside of the barrel. I've used the method before, but moved to the cooperage recommendations for no other reason than because that's what they say to do.


We do outside of the 'back' and inside of the 'front' head at the same time. Coopers probably recommend inside for the same reason we do it this way, it keeps the the logo and stuff on front looking good.


If your water has any unpleasant taste then use RO or carbon filtered.

I always drive the hoops down tighter. If they have dried out the hoops will move quite a distance.

I put in about 4-5 litres of hot water. I have a football pump needle pushed through a silicon bung. Pump a couple of psi into the cask and withdraw the needle until the end is inside the bung which stops the air escaping. Roll the barrel and water and/or bubbles will show any leaks. Air forces water into cracks and the wood swells and seals very quickly.

You don't need much air pressure, I have never blown a bung out but I guess it is possible, maybe into an eye, ouch!