Transferred 10-11 gallons of our latest IPA (cold, after a 4 day cold crash) to 2 corny kegs about a week ago. I blew some CO2 into the keg (no regulator, just opened the valve on my small tank), then filled with the cold beer on top of a muslin bag of the first round of dry hops, the hit it again with another small amount of CO2 directly from the tank (maybe 1 second of the valve open). let the dry hops sit for 4 days at ambient temp (65-70*), occasionally bleeding air off. The kegs were pretty full, but below the CO2 dip tube.
When I went to add the second round of dry hops on Monday night, I tried bleeding the kegs to get the lids off, but it was a foamy/beery mess! I’m not sure how so much foam was created, but maybe I had more CO2 trapped in there than I thought and it was absorbed back into solution? Ended up hooking up one of the kegs to my beverage line and running about 3 pints worth out of it to get rid of some of the headspace and actually get the lid off, but it was still foaming and violently spraying through the blowoff valve and the ‘CO2 - In’ connect.
Had a pint of the beer cask-style as it had a decent amount (maybe 1 volume) of CO2 dissolved in it. Tasted great, no hints of pedio/aceto or anything. What did I do wrong?