[wyllys]

I got a 5 liter barrel for aging spirits for Christmas and I want to use it to barrel age a homebrew stout. Normally I do all-grain brewing, but I am considering just doing a small extract kit for this one as an experiment.

Does anyone have advice on the best way to go about this?  Mostly Im wondering how to carbonate in the mini-barrel without blowing out the stoppers.  I figure I would transfer about a gallon or so (just short of 5 liters) to the barrel after 2ndary fermentation is done, but that's where I start having questions - how to carbonate properly, how long to leave it in the barrel?  Because the barrel is small and the volume-to-barrel-surface ratio is much larger than in a typical aging barrel, the flavors are transferred much quicker.

thanks!

[ynotbrusum]

Other than stainless firkins and pins, which have special things called spiles for fobbing, thus producing cask conditioned ales, I know of no one attempting to carbonate in a keg, especially not a wooden aging keg.  You are right about the smaller vessel aging the barrel flavor faster, though.  Someone here with cask experience can possibly address using a wooden keg in this manner...if the spiles can be used on that scale, etc....

[tomsawyer]

I've put carbonated beer in a wooden cask (3gal in this case) and served it that way.  If you try carbonating, be sure you hammer the bung and tap in good first and go for a low carbonatino level.  You have a chance but this isn't ideal by any means.  I think you're safer racking in pre-carbonated beer.

[morticaixavier]

I'll only add that you want to fill the barrel completely. this become more important with small barrels. In my opinion the problem with smaller barrels is not so much the speed at which the beer picks up oak character. I've said before that you can actually leave a beer on oak for quite some time. after the initial period where it can get harshly over oaky it will mellow and get better and more complex.

The problem with small barrels is 02. The surface to volume ratio of the barrel to beer is so much smaller with a small barrel that even though the total surface exchanging air with the beer is much smaller it will still get a lot more o2 and thus oxidize much much faster. If you leave ANY headspace in the barrel it will happen even faster, faster than you likely want.

I think your idea of brewing a simple extract with grains is fine if that's what you want to do. or brew a full batch of AG stout and rack into the barrel just the ~5 liters you need to fill it to the brim. Keep the rest aside in a purged secondary to top up as you taste and as the beer evaporates through the oak.

[svejk]

I've never heard of anybody trying to carbonate in a small barrel before, but I suppose you could do it by putting a strap around the barrel to hold the bung in place.  That said, my suggestion is to fill the barrel with whiskey and brew a full 5 gallon batch of imperial stout.  Rack the beer to a secondary and let it bulk age for a few months or so until it is tasting great.  At that point, the barrel will be well infused with the whiskey flavor, so you can rack the whiskey out and put the beer in. 

As mentioned above, the beer will be infused with the barrel flavor very quickly so you should taste it every week or so to see when it should be pulled.  If you find that you overshoot your target for the barrel flavor, you can blend it back with some of the base beer to hit your target.  The great part about this plan is that you can give the barrel a rinse and put the whiskey back in it to get ready for the next batch. 

I've done this myself with a 2.5g oak barrel and it has worked very well.  I do find that using kegs makes that whole process much easier, so if you don't have a kegging system it might not be practical.

One other thing I wanted to mention is that if you do plan to rack pre-carbonated beer into the barrel, you may end up with excessive foaming (think mentos and diet coke), so you'll want to plan accordingly.