I am currently doing my first batch in a corny.
I put in 4gal and rigged up a blow-off tube like Charlie Pap shows in "The Homebrewer's Companion". My brew day went really well, so I was kind of crestfallen when I was not seeing any action out the blow-off tube after two days. Hard to tell what is happening in there! But, on Day 3 of the ferment, I started having CO2 farts escaping to the blow-off tube/growler half full of StarSan. :rockin: It is a LOT of headspace to fill with 1.5gal in the keg and a 4' run of 5/8" ID tubing!
I am rushing this batch a bit in order to try and get it ready in time for a buddy's Holiday visit, so I transferred it last night (rather than waiting for the full three weeks...recipe says ferment 1 week and then bottle) with a CO2 push onto 1gal of water that was boiled, kegged and purged with CO2 the night before. I captured exactly 8oz of trub before the line started running "clear". I've been reading about this method for a while now and have seen a fair bit of back and forth on whether to cut the dip tube or not. Half a pint of trub at the start of a transfer tells me that cutting the dip tube is not needed (I am using a hop spider and am starting to play with whirlpooling). Anyway, I did my transfer at about 10psi and it took about 4 minutes. That left me with nothing but my transfer hose and the two QDs to clean up. No auto-siphon or 6' hose to wrestle with. No inevitable spillage.
I opened the fermenter and added my yeast wash water, shook it all up and then pushed this out with CO2, as well. I seriously need a 1gal jar for this stuff. But, even with the half pint captured at the start, my total take of trub was 1500ml with 1qt added to wash. I haven't done the conversion yet, but I think this shows that there is very little left over (read: wasted) beer in the bottom.
I took a look at the band left from the krausen. It was only about 3/4" thick. I boil with Fermcap-S, but did not add any to the fermenter. As this was far less thick than I was expecting, I feel pretty safe in bumping my next batch up to a full 5gal into the fermenter.
In all, I am done with carboys. I have a pile of the blasted things (about a dozen) clogging up my garage. I'll probably hang on to two 6.5gals and a 5gal...just in case...but the rest are being given away to friends who are getting into brewing, or are going back to the LHBS from whence they came. Hell, the grains and hops for this very batch were paid for in trade for a 5gal carboy at the shop! Free beer! :cross:
I'll play around with this a bit more. Once I am comfy stepping it up to 5gal with the blow-off tube, I might try the airlock in the pressure release route. But make no mistake, I am heading towards pressurized fermenting in a corny keg.
So happy to be done with the glass. Once you break one of those buggers while cleaning it, you will know what I am talking about.