The Science behind the Spice

Why does the chili burn my mouth so? It’s a question that I get asked all the time and there is actually a very scientific response. 

Chili burns because of capsaicin, a chemical compound found in chili peppers. 

Capsaicin binds to TRPV1 receptors in your mouth, which normally detect heat and pain. These receptors send urgent signals to your brain, tricking you into believing your mouth is literally on fire – even if you’re sucking on an ice pop in the Antarctic. 

Capsaicin is the culprit

The TRPV1 receptor is a pain and heat-sensing receptor found in nerve cells, particularly in the mouth, skin, and digestive system. It acts like your body’s thermostat, detecting high temperatures, physical abrasions, and irritating chemicals—like capsaicin from chili peppers.

Normally, it detects heat above 42°C.

Capsaicin hijacks the system by binding to TRPV1, tricking your brain into thinking you’re experiencing actual heat.

Your body reacts accordingly—sweating, tearing up, and trying to “cool down” as if you’re on fire.

TRPV1 is also involved in inflammation and pain perception, making it a key target for painkillers and medical research. Some scientists are even looking into TRPV1 blockers to help people with chronic pain conditions.

Chilis contain capsaicin the active ingredient that provides the burn

Fun fact, some animals have these receptors and some don’t. Birds don’t, if they did they wouldn’t be able to eat the fruit and disperse the chili. Dogs do. So unless you want Rover breathing fire and treating your house like a sewage works skip the Habanero salsa and stick to the Pedigree Chum.

In conclusion, although it may feel like our mouth is on fire, it´s all just an elaborate trick out body plays on us to keep us safe.

And if you do over do the extremely spicy Maracuyá con Reaper hot sauce, remember milk and yogurt are your allies. Lactose binds to the capsaicin proteins and neutralise them providing you with some relief. Just don’t ask for the hot sauce flavour.