Food and heat perception

Scoville Heat Explorer

Scoville Heat Units describe chilli pungency. They do not measure temperature. Use the explorer to place a value on a broad descriptive scale and then see why capsaicin can produce a burning sensation without making food thermally hotter.

Explore a Scoville value

Why chilli can feel hot without being hot

Capsaicin activates TRPV1, a sensory ion channel involved in detecting noxious heat and other stimuli. The nervous system can therefore interpret capsaicin exposure as burning even when the food itself is close to room temperature.

Scoville ratings are not thermometer readings

A sauce rated at 100,000 SHU is not physically hotter than one rated at 5,000 SHU unless their actual temperatures differ. SHU and degrees Celsius describe different quantities and cannot be converted into one another.

Representative ranges need context

Named pepper varieties are often associated with broad Scoville ranges, but those ranges should be treated as descriptive rather than guaranteed values for every pepper. Laboratory measurements provide a result for the tested sample.

Sources and further reading

The capsaicin receptor: a heat-activated ion channel in the pain pathway - foundational TRPV1 research indexed by PubMed.
NIST Chemistry WebBook: Capsaicin - chemical reference information for capsaicin.