The pot is made of clay which retains heat, and the double lid generates the right level of pressure inside the pot to cook each grain of rice evenly. The pot's ceramic material releases far-infrared radiation which heats the ingredients inside. Putting the pot over direct fire increases this effect, resulting in a fluffy textured rice. The rounded shape of the pot creates convection for each grain of rice to be cooked evenly. Having both the inner and outer lids generate the right level of pressure inside and prevents contents boiling over.