Sichuan pepper makes your lips buzz at 50 Hz
It isn’t a pepper and it isn’t hot. It makes your mouth tingle, and researchers found the tingling feels like a vibration of about 50 times a second.
Eat a dish from Sichuan and two sensations arrive together: the burn of chilli (là) and a strange tingling numbness (má). Together they make málà, the signature of the region’s food. The numbing part comes from Sichuan pepper.
Not a pepper
The husks come from shrubs of the genus Zanthoxylum, in the same family as citrus and rue. That’s why they smell lemony. They’re unrelated to black pepper or chillies, and they aren’t actually hot.
A spice you feel as a vibration
The active molecule, hydroxy-alpha-sanshool, excites nerve fibres that normally sense light touch and vibration. Your lips feel as though they’re buzzing.
In 2013, researchers at University College London tested how strong the effect was. Volunteers put Sichuan pepper on their lips and then matched the sensation to a mechanical vibration. The tingle matched a frequency of about 50 Hz: fifty pulses a second. It works like a vibration your nerves perceive without any movement.
Why it’s on the menu again in America
From 1968 to 2005 the US banned imports, because the plant could carry citrus canker, a disease of citrus trees. The ban was loosely enforced, but Sichuan food in American restaurants was often made without it, so many people only discovered the real má in the last couple of decades.
Before chillies reached China in the 16th century, Sichuan pepper was one of the main sources of pungency in Chinese cooking.
Bring it up
“Sichuan pepper doesn’t burn. It vibrates. Scientists measured the tingle at about 50 Hz.”
Follow the thread
- RelatedA noodle dish whose name has 58 strokes Another pillar of western Chinese flavour: chilli oil, garlic and spice.
- In contrastGeneral Tso’s chicken is unknown in General Tso’s home province Authentic regional Chinese flavours versus their Americanised versions.
- In contrastSpicy isn’t a taste. It’s pain. Chilli triggers heat-pain receptors; Sichuan pepper triggers touch receptors. Málà combines both.
- RelatedUmami: the taste discovered in a bowl of soup Another case of a cuisine’s signature sensation being traced to a specific molecule and receptor.
- RelatedBefore 1492, Italy had no tomatoes and Thailand had no chillies Sichuan pepper gave Chinese food its tingle long before chillies arrived from the Americas.
