Magnetic stirring is a device that consists of a stirring plate – a flat surface with a rotating magnetic field - and a rotating magnetic stir bar that is located within the container of liquid that is to be mixed or stirred. The stirring plate may be heated or unheated, depending on the conditions required, and may come with porcelain, stainless steel or cast iron as its surface. The speed of the magnetic stirring may be controlled either manually or it may be programmed to a pre-set requirement. The stir bar that is placed inside the container holding the liquid to be stirred is a magnet of various diameters and lengths and may be coated with Teflon or some other non-reactive, durable material.