It can be done in a pot directily on the stove burner. However, with this method, you really cant walk away from it for very long without risking burning the soap. I've done this HP method a lot and I never burned the soap though... I just take car to keep folding the soap every now and then so the same stuff doesn't stay on the bottom the whole time... and I keep the burner on low, low-med; if I turn it up, its only in short bursts while I'm standing there. Theres also another method that involves a double boiler. A special double boiler pot isn't even necessary. All you need is a bigger pot, put 3 empty tuna cans in the bottom (to elevate the smaller pot the soap is in) and voila, double boiler. You ony really need a couple inches of water. I've even hp-ed with steam; the top pot was the same size as the pot with the water, and made to sit on top of it, so all the heat hitting the bottom of the soap pot was just steam.