I’m looking to bump up to 10 gallon batches, at least some of the time. I currently use am 8 gallon megapot, and it’s only barely acceptable for 5-6 gallon batches, to begin with. I am wondering if I should get a 15 gallon kettle (that would allow me to bump up to 10 gallon batches), but I don’t want to spend the cash if I will only be able to use it for 8-12 gallon batches and not 5-6 gallon batches. Is it a PITA to brew 5-6 gallon batches with a 15 gallon kettle?
I do it all the time. No issues, no worries about boil overs either.
The only downside I’ve experienced is a little more boil off due to the larger diameter of the pot. To be honest, if I had it to do over, I would buy a 20 gallon pot. I’ve had to use another pot a few times due to the larger initial volume for long boils. Not a big deal. Just an inconvenience. Cheers!
+1
I use 15 gallon kettles for both 5 and 10 gallon batches. I have also made 12 gallon batches using the 15 gal kettle.
That’s what I thought the first time I used one. I was quickly proven wrong! 
I think 15 gallon is perfect for those 5-6 gallon batches. And 20 gallons would be better for 10…
It looks like I can get a 15 gal megapot for a little under $230 (including shipping), and that’s the best deal I could find. Any reason why I shouldn’t get it?
If you don’t mind Aluminum you can find for half that or less.
As far as pulling the trigger:
Dooooo it… You’ll be pleased with the performance.
+1…my homemade electric keggle is 15 gal, and the majority of my batches have been 5 gal.
No worries.
If you can do without a lid, the Penrose Kettle is 16+ gallon, stainless, 14 gauge, with a half inch ball valve for only 139.99 which includes shipping to the lower 48 states. Details email me at dpenrose at essexind dot com
Seen folks on here recommend this site before. Looks like ~$140 plus shipping…
http://www.instawares.com/stainless-steel-stock-pot-sps-60.upi-sps60.0.7.htm