I organized a project for my brew club, the Ann Arbor Brewers Guild, to fill an empty bourbon barrel with a barley wine of about 9% abv. Twelve of us brewed five gallons from the same recipe. More details about that on another thread in the non-whiskey alcohol category, perhaps.
But I thought this was interesting. We got an ex-Elijah Craig 12-year-old barrel in January from a homebrewer in Madison, Wisconsin who picks up a truckload and distributes them to microbreweries. He offered us one at a great price - $60 delivered.
I stored it in my garage until we could all brew our batches, and wanted to keep it moist so it wouldn't dry out and leak. The garage was cold and the relative humidity fairly high, but I wanted a little insurance, so I dumped in a liter of Cabin Still that I had picked up in my travels and was disappointed in. I rolled the barrel around every few days and tipped it end for end to try to moisten all the interior surfaces.
We filled the barrel yesterday and dumped the bourbon out first, filtering it through a dozen layers of cheese cloth to remove the charcoal. We ended up with only ~300 ml (some was probably lost in the cheese cloth).
I was amazed at how dark it was - almost black, but then I realized that it had a haze of suspended charcoal dust. So I filtered it through a coffee filter. I think it was still darker than the original.
I tasted it and nearly choked - I was expecting the 80 proof I had dumped in, but it was way stronger. I checked it with my refractometer, and it was above the scale, but by interpolating above the scale, I estimated it to be 115 proof ±3.
So, what happened? I suspect that it mixed with the EC12 that was still in the char. That would be at barrel proof, probably ~130. Or, maybe there was an accelerated angel's share with the corresponding increase in proof.
With watering down to ~80 proof, I think it was better than the original, but it still tasted like a young whiskey - some feinty notes remained. But it seemed a bit richer. Still had the HH trademark menthol or eucalyptus or teaberry/wintergreen.
But it wasn't EC12. I tasted that afterwards and there was no comparison.
So I guess now I have a slightly improved, closer to barrel-proof Cabin Still. It may make a nice manhattan.
BTW, the barley wines all tasted great going into the barrel. I am looking forward to following the development of the blend.