The Original Gongfu Tea Stove for Boiling Water. The tweets is there for starting the fire. The real fuel is charcoal made from the pit of olives. These pits have nuts inside, which carry oil substance, they give out an unique light aroma when burned. Through the air permissible bottom of the clay pot, the aroma finds its way into the water, giving the water the abiilty to enhance the Hui Gan (回甘= Return of sweetness) of the tea. These olive charcoal also burn very slowly.