Finally got tired of trying to boil 7 gal of wort in a 7.5 gal BK, so I picked this up at the LHBS tonight:
15.5 gal should keep the wort in the kettle and off the ground.
Yeah, although I had a boil over today with 6 gallons in a 15G keggle… :o (needless to say I wasn’t paying attention…)
So even with the 15.5 gal, it isn’t “set it and forget it”? 
Depends. If you’re doing a 5 gallon batch less risk, but getting 10 gallons into the fermenter out of a 15.5 BK- no. Not enough room for the foam to collapse back upon itself. Though with anti-foam, as the foam begins to rise- hit it with a few drops and bam! No more foam and you can walk away. Then there’s how vigorous the boil is. Still might splatter a bit. I went for a 20 and have to watch it like a hawk if I put 15 gallons into it. I had it nearly to the brim with 18 on more than one occasion. Woohoo. Keep a few towels handy…
Have fun that is one gorgeous kettle.
Thanks Euge!
I may occasionally do a 10 gal batch, but don’t really plan on it. I was just tired of having to sit right next to the pot during a boil on boil over duty. On a 60 min boil I usually have just over 7 gals of wort and for a 90 min boil I have almost 7.5 gals; it just got too frustrating for me. Hopefully this will let me do a bit of cleaning while boiling the wort.
Plus it’s shiny! ;D
I’ve always wondered how those kettles are. Is the SS pretty solid?
I too was doing 7 gallons in a 7.5 gallon kettle, but ungraded to a 10 gallon Megapot. Even now it’s still pretty close to the top ( boiling 8-9 gallons of wort to end up with 6 ), but a few drops of Fermcap-S puts my mind at ease a bit.
Hey, Euge is this the stuff you’re talking about?
http://www.williamsbrewing.com/ANTIFOAM-P2235.aspx
It says a few drops in and Erlenmeier… how’s that translate to a keggle?
Shouldn’t make a difference. I’m pretty sure it’s the same as this:
It also works very well for the boil.
I use this: Five Star Defoamer 105 (similar to Fermcap-S)
I recently got the 6 gallon version of that kettle that I was planning to use as a fermenter but it leaked like a sieve at the handle rivets :(. I thought it looked and felt like a good kettle, but I was quite disappointed with it.
It’s most likely the same as this
Except I have a 16 ounce bottle of it, a lifetime supply.
I use it in the boil - three or four drops stops the boil-over.