Got some Briess Dark ferm'ng in a 5 gal Corny AWS(as we speak). Started using keg 'cause had only 1 BB 'boy, and price of those 'boys is ridiculous! Why buy BB when used keg is $40, and is indestructible??? It's my 2nd batch in keg, and no overflow, which was a concern. Kegs are near indestructible, and, if temp is not optimum, they can be cooled or warmed FAST. Batch can be made in portions, with ingredients added stepwise, if necessary. May even be a useful method to cool hot wort?? Rough on the O-rings, so what? Volume of wort started at 3.75 gal, as I was concerned about overflow, but it was chilly in room last nite, so slowed it down. Plan to add some carapils solution, later, then again, and transfer to 6gal Vintage House 'boy. Access and exhaust is done like this: I usually san'ze top, and leave it in-place during entire ferm. Use the standard in and out tubes, not using the poppet posts. Remove the O-rings, stretch a length of gum rubber tubing(lab supply) about 1/2 in down over the flare, put in hole, wrap with plastic wrap, and now you have 2 access ports, one to below and one to above the liquid level. You can gas, take samples, add more stuff, whatever. I have a bubbler stuck in the shorter tube, and the little darling lulls me to sleep. Yes, yes, the yeast. An occasional swirl, and the yeast settles on the bottom, so, yes, genius, you DO have to be careful where place the out tube.