How a Slow Cooker Works
An authentic slow cooker is a simple, uncomplicated appliance with no moving parts. Even though you most likely know what a slow cooker looks like, this list breaks down the parts of every slow cooker:
Transparent cover: Most slow cookers have a heavy glass lid, but some are plastic. Always cover the slow cooker when cooking, to retain heat. The clear lid lets you look in, eliminating possible heat loss from having to remove the lid. The heavy weight of the lid creates a tight seal.
Highly glazed stoneware insert pot: In keeping with the original Rival Crock-Pot design, most true slow cookers have a removable, highly glazed, thick round or oval ceramic stoneware pot (called a crock).
Wrap-around heating elements: The low wattage, wrap-around, electric heating elements are encased between the outer and inner metal housing and never make direct contact with the stoneware crock.
Metal wrap-around housing: The base of the slow cooker is made up of a double-walled metal housing that contains the heating elements. Because the heating elements never make direct contact with the stoneware insert pot, there are no hot spots, eliminating the need for stirring.
Variable controls: All slow cookers have dial controls on the front. They usually include off, low, high, and perhaps auto or keep warm.