I have a 7.5 gallon stainless steel brewpot and when doing large boils my stove has trouble keeping a rolling boil. My question is whether it is safe to have a the brewpot over two burners since some of the flames will be going up the side of the pot. Thanks and cheers!
I have done this exact same thing. There was not too much flame extending out from under the kettle, but I used a pretty wide kettle to begin with. After I had acheived a boil I moved the kettle (very carefully!) over one burner for the rest of the boil. You won't get a mad boil but it will do the trick in a pinch.
Some things to note: keep a spray bottle of water on hand to combat boil-over foam. My wife did not care for the results of my first attempt and it took a really long time to clean all my boil-over off. Oops.
I did this twice before moved outside to a turkey fryer burner. Again, Be extremely careful!!!