I have a High Gravity 120v with a 2200 watt boil coil element.
I start with 7.25-7.5 gal mash water and it takes 1 hr to get to mash Temps. Depending on your water temp it could take less or more time but for me 1 hr is the norm.
Clawhammer uses a 1600 watt element i believe so it will take...