How big of a pot do you need to brew 5 gallons beer?

A 5-gallon batch of beer requires a boil kettle with a minimum capacity of 7.5 gallons. This will allow for enough space for the wort to boil vigorously without boiling over. It is also important to consider the size of your fermenter when selecting a boil kettle. The boil kettle should be large enough to hold the entire batch of wort after boiling, plus an additional 1 gallon of headspace.