Kolsch gusher

The other day I purchased a 0.5 liter can of Fruh. Just opened it…and it was a gusher.

I don’t get it. Kolsch is pasteurized and filtered, isn’t it? Why should it gush?

I looked at the Best Before date on the bottom of the can, and it was September 16, 2020, so it was past its prime.  Although it tastes fine…quite delicious, actually.

I am an idiot. Beer was too cold. I had it stored in my unheated Montana garage, and that I have a gallon jug of water unfrozen in the garage made me think that beer would be fine. But the water jug is located in a distant location.

Nevermind.