darnit - jumped the gun... what would you do?

I kegged two brews yesterday after 10 days in the primary. An IPA and a Blue Moon clone. The IPA was ready so no problems, but when I cracked the top on the BM clone, it was obvious it was actively fermenting - the top was one big bubble field. So I racked it to a keg anyway and have it sitting in the closet. I'll vent it daily for another 2 weeks and then force carb it.

But in retrospect, I probably should have put the top back on. I was concerned though that I already let all the CO2 out and wasn't sure what that O2 layer would do to the beer. So I figured kegging it and purging with CO2 would be safest.

What would you have done in this situation?

Hydro reading was 1.018 so it was close to being finished.

Did you purge it when you transferred to the keg? If so O2 shouldn't be a problem. As for letting it finish up in the keg that is no big deal either. Many people secondary (or even primary) in kegs.

Yeah I purged it and I don't mind secondarying in the keg I just don't like to naturally carb it so I need to vent it daily to keep the pressure down. I just never had one so obviously not done carbing when I opened it up from the primary. Must have been a bit cold where I had it.

I've seen some setups for kegs where there is a carbonation lock on the post of the keg. Are these homemade or can I buy them somewhere?

You can buy them but they should be pretty easy to make too. That or just hook up a blow off tube... all you need is a gas disconnect and a couple feet of tubing.

I sometimes do a primary fermentation in a corny keg... all you need to do is remove the gas-in post and the little insert thingy then connect a bit of tubing to the keg post and run that into a bucket of star san. Works great as a blow off.

Sometimes, I don't even remove the post itself. I keep the post on and hook the gas out to a gas lock and tube to water. Then when it's done, transfer from keg to keg using the liquid posts.

However, if you want to consider naturally carbing the beer, you may want to look at getting a spunding valve. Get the adjustable one that allow you to set a desired psi so that anything above say...20 psi will vent. You can both make or buy these. For me, shipping the individual pieces was more expensive than buying the thing.