Your outlet is similar to this one from Grainger
in that it is a 50A 240V outlet. Your outlet is being run from a 40A circuit breaker. I suggest that you change out the circuit breaker to a 30A 240V breaker. GFCI breakers are fairly expensive and if you were to place one in your mains panel it would require you to replace the wiring and the outlet that you would be using. A far less expensive solution is to use a standard breaker and then secure a Spa Panel. It is critically important that your brewery be GFCI protected.
You would need to get a range power cord like this one from Lowe's
and then wire that to the GE Spa Panel
and then set it up to be plugged into your 240V outlet - like this:
Then set up your controller this way:
(Click on the image to see a full scale diagram that is printable on Tabloid paper (11" x 17")
This way you only need one PID, one SSR and one heat sink for it, all available from Auber Instruments. A bonus is that the whole thing will fit in the Project Box
also offered by Auber Instruments.
I hope this helps you.