Sichuan pepper makes your lips buzz at roughly 50 hertz
Sichuan pepper is not a pepper at all. It is the dried husk of a citrus relative, and its signature tingle has been measured as feeling like a vibration of about 50 hertz on the lips. Food writer Harold McGee compared it to licking a nine-volt battery.
The spice, huajiao in Chinese, comes from the outer shell of the fruit of Zanthoxylum plants, which belong to the same family as citrus and rue rather than to black pepper or chillies. Cooks usually use it dried: the shiny black seeds inside are thrown away with the stems, and the empty husk is the part that goes into the pot. Fresh green fruit can be used too, and the leaves turn up in soups and fried dishes.
The buzz comes from a compound called hydroxy-alpha sanshool. McGee suggests sanshools stimulate several kinds of nerve endings at once, making nerves that normally ignore touch and cold suddenly respond, a sort of general neurological confusion. The flavour itself is citrusy. Combined with chillies it creates mala, the numbing heat at the heart of mapo doufu, Kung Pao chicken and Chongqing hot pot. It is also ground into five-spice powder, infused into oil, or toasted with salt in a wok to make a condiment for duck and pork.
Its range stretches well beyond Sichuan. One species, Zanthoxylum armatum, grows along the Himalayas from Kashmir to Bhutan; Nepalis call it timur and season momo dumplings with it, while in Bhutan and Tibet it flavours chutney-like side dishes and blood sausages. Relatives supply other traditions: sancho accompanies Korean fish soups, andaliman goes into green sambal in Indonesia's Batak cooking, uzazi comes from an African species, and in Assam a variety is used as a herb.
Traditional Chinese medicine lists Z. bungeanum in the national pharmacopoeia for complaints from toothache to eczema. Evidence-based medicine, however, recognises no accepted use for it. Laboratory work on animals and cell cultures has found pain-relieving, anti-inflammatory and antibacterial effects, but those findings have not been established in people.
Source: Sichuan pepper
