Bottled my "tan" - very bubbly?

[iadams]

My dad and I are brewing the components of a balck and tan. He brewed his Porter, and I brewed a tan lager style (I used a lager like ale yeast).

Anyway, at bottling time, the beer in the secondary had a lot of gas in it, which when placed in the bottling bucket almost looked like finished beer (as in carbonated beer). I am not worried about any ill-effects, and it settled out within 10 minues, but I am curious what causes this to happen in the secondary.

Ian

 

[Baron von BeeGee]

Backpressure from the airlock causes some of the CO2 to go into suspension in the beer instead of escaping through the airlock. This is the basic idea behind cask-conditioned ales...if you have an airlock that causes more backpressure the CO2 will carbonate the beer to a certain level and the excess will build up enough pressure to vent out.