I used a laser infared thermometer initially to get the temperatures correct. You do NOT want to heat alcohol up too much, the boiling point is 172F, VERY LOW! If the alcohol begins to bubble, then remove the glass jar from the heat source as the pressure buildup is not safe (a big reason why I use the thickest glass mason jars). The heat step is just to make absolute sure I am getting the most out of the extraction, although it is not completely needed, so if you are worried, then remove the water bath heat step and simply leave out at room temperature for an extra 30min-1 hour