4 gallon boil- 5 gallon pot

I brought a burner 4 months ago intending on buying a 15 gallon kettle soon after, things came up and unfortunately a two hundred dollar kettle is not in my cards right now. I’d like to give the burner a go but only have the 5 gallon pot that I use on my stove. Is a 4 gallon boil a recipe for disaster or is it possible if I’m careful?

Its possible. Just be careful and diligently watch the start of your boil. Might be a good idea to have a spray bottle handy to spray as the hot break rises.

Keep the heat medium-low for at least the first 10 minutes of the boil. After that, the foam from the hot break falls back into the wort and you can crank it up as far as you want, limited only by the bubbles leaping out of the kettle. Find a good balance point where it’s not all jumping out and then just let it go. It will only boil over in those first 10 minutes. After that you’re pretty safe.

I boil 6.5 G batches in a 7G BK on a propane burner.
Repeat after me- “Fermcap-S is my friend”.
Also, as Dave said, keep a weather eye on the pot. As soon as you start to get the hotbreak, crank that baby down. Keep it just at a slow rolling boil.

Another thing is turn off the burner when you do your additions and stir them in before turning the flame back on.