What You Need to Know
The technique relies on the latent heat of water: as the water slowly evaporates, it absorbs heat and keeps the interior at a constant temperature. The thermal gradient between the hot inner pot and the insulated outer chamber reduces heat loss by more than 90 % compared to an open pot, allowing the food to cook gently while preventing bacterial growth.
The Science
Primary Reaction
Heat transfer via latent heat of water evaporation and conduction through insulation