I just brewed 10 gallons of Imperial brown ale. OG was 1.070 and after 2 weeks in primary it was down to my targeted 1.016. I racked half the beer into a secondary carboy and the other half into a freshly dumped 5 gallon oak whiskey barrel, I was not able to completely fill the barrel so I topped it off with CO2 in the head space. 3 weeks later I went to take samples and got a bit of a surprise. The carboy was still sitting at 1.016. So far so good. When I removed the bung from the barrel I heard a "pop" as co2 escaped the bunghole. When I looked into the hole there was some kreusen that was slowly rising and making it's way up to the hole. I recorked it and after a few minutes it had settled down enough for me to take a sample. The SG was down to 1.011. I automatically assumed it had gotten contaminated and had bugs in the barrel (Is this common for whiskey barrels?) but upon tasting it I did not detect any off flavors. I am a certified beer judge but that doesn't mean I pick up every little problem with a beer, however I would think I be able to detect lacto, or brett or anything that would cause a secondary fermentation in a whiskey barrel. Does anyone have any experience with what may have happened here? This is the first time I've used a barrel, so this is all new to me. Thanks in advance.
P.S. the beer in the barrel was very slightly carbonated so that could have affected my hydrometer reading but I would think carbonation would cause a higher reading rather than a lower.
It also occured to me that water from the beer could have escaped through the walls of the barrel since I live in a very dry climate here in NM. but that would not explain the carbonation and CO2 build up in the barrel.
"The ordinary world is only the foam on top of the real world." Tom Robbins (B is for Beer)
"It's a beautiful day for baseball. Let's play two." Ernie Banks