I turn the thermostat all the way up. The cup sizes shown are 1 cup(will hold 2), 2 cup, and 4 cup Pyrex. I haven’t had one break but have read that it can happen. I microwave on the initial heating and will heat my injector up with a torch or set it in the pot. After injection evacuate your injector back in Pyrex and set the injector back in hot plastic. Stir occasionally with injector.