How Fieriness Works

Fieriness isn’t one of the five canonical tastes. It’s not a literal spike in temperature inside our mouth. This is an illusion; the “heat” is a sensation. Scientifically, it’s a phenomenon called chemesthesis: the body’s response to irritation. Throughout our body, including our mouth and nose, are sensory receptors that constantly scan our environment for changes in temperature (thermoreceptors), pain, and pressure (mechanoreceptors). When you take a bite out of a fresh or dried chilli or a black peppercorn, specific chemicals in these ingredients attach to these sensory receptors, which get irritated and trick the brain to produce a sensation of heat and pain. You feel a desire to drink water to wash away the feeling of intense heat. Over time, by gradually introducing hotter foods, you can develop a tolerance as your pain receptors adjust. Many of us have learned to love this perception of heat and associate it with deliciousness.