Japanese Sansho Pepper: Kinome, Kona-Zansho and Citrus-Numbing Spice
Japan — nationwide, mountain regions (kinome from spring shoots, berries from summer-autumn)
Sansho (山椒, Japanese pepper, Zanthoxylum piperitum) is one of Japan's most ancient and botanically unique spices — a member of the citrus family (not the true pepper family) that produces both edible spring leaves (kinome, 木の芽) and small berry husks that are dried and ground into kona-zansho spice powder. The active compound is hydroxy-alpha sanshool, which creates a remarkable neurological sensation: a tingling, numbing effect on the lips and tongue (similar to Sichuan pepper, to which it is closely related) combined with a bright, citrus-herbal fragrance and a clean, fresh heat that is completely different from chilli-based spice. Kinome (the young spring leaves) are the most delicate and aromatic form — they appear briefly in April-May and are used as garnish (placed flat on dressed food), as a crushed paste (kinome-ae) for spring aemono preparations, or floated on clear soups as a seasonal signal. The dried berries are ground into kona-zansho (粉山椒) — Japan's table spice for unagi (eel), yakitori, and noodle dishes. Whole green berries in early summer are simmered in soy and mirin to produce tsukudani-style sansho (another covered elsewhere), used as a condiment with rice. Sansho's uses span the full seasonal calendar — a uniquely complete spice that changes form and application through the year.