Demystifying Sansho

By Andrew Englehardt

It is not uncommon that when speaking on the subject of Japanese cuisine you might hear someone say “Japanese food just isn’t spicy.” While Japan might seem to stand out among neighboring Korean, Chinese, and other Southeast Asian cuisines with strong traditions of spice, it seems unfair to claim so generally that Japan does not utilize the pepper. As I began to rack my brain, trying to land on what might possibly be the iconic Japanese pepper, the lemony, mouth-tingling sansho came to mind.

Fresh sansho berries and kinome leaves (Photo by 後藤しおり, Shiori Goto)

Perhaps the joke is on me after all, as I soon discovered that the essential Japanese pepper is in fact no pepper at all. Sansho (山椒), “mountain pepper” or hajikami – all names by which it is known – is taxonomically a member of the Rutaceae family, making it a citrus! Just as the peanut is no nut and the blackberry is no berry, sansho is no pepper by any genealogical standard.

With that as a start, it’s not surprising that sansho finds itself at the center of an often confused family tree. In short, while qualitatively it shares similarities with its relative ‘Sichuan pepper’ – a broad category that includes Z. Schinifolium, Z. Simulans and Z. Bungeanum – sansho (Zanthoxylum Piperitum) is not simply the green version of a red ‘Sichuan pepper’.[1] This might be a lot to quibble over if all these species lent themselves to more or less the same application in food, but they do not! While sansho pepper has frequently been described as uniquely lemon and grapefruit forward, some of the aforementioned species instead have anise, rose or casia qualities.[2]

Sansho Harvesting (Photo by 後藤しおり, Shiori Goto)

Before delving into all of its applications in food, it is best to understand the life of the sansho plant itself. Cultivated primarily in the mountains of Japan’s Wakayama region, the Z. Piperitum tree stands short and develops a wide canopy. While most members of the prickly ash family grow thorny branches, the asakura sansho – a variety imported from Korea and the main variety grown in Japan today – has smooth bark.[3] That bark, as well as the roots, leaves, flowers and seed hulls of the plant are put to use in a variety of ways.

Young leaves of the sansho begin to appear in March and April, and are picked as kinome (木の芽), a popular Japanese yakumi, or garnish. In preparation, the leaves are ritualistically smacked between palms which is thought to help release the oils responsible for its citrusy fragrance. Then, in dishes like takenoko gohan, or bamboo rice, the leaves might be simply placed on top as a final touch, adorning it with a delicate beauty. In other cases, kinome is incorporated more prominently as an ingredient. In kinome-ae, bamboo shoots are cooked in dashi and dressed with a sauce of white miso and kinome.

Kinome-ae (Photo by Makiko Itoh)

Later in the season, the flowers (hana-sansho) of the male plants, and the seed pods of the female plants are harvested. When they are young, whole fresh seed pods known as mi sansho are harvested for use in an array of dishes. One of the most simple treatments for mi sansho might be lactic acid or vinegar pickling. Another familiar example would be sansho no tsukudani, a straightforward braise of fresh sansho berries in soy sauce, sake, sugar, and rice vinegar. While such a large quantity of sansho might otherwise be overwhelming, heat from sustained cooking denatures most of the components responsible for sansho’s uncanny mouth-numbing, tingly quality that it is known for.[4] However, this should not be confused with the spiciness of capsaicin in chili peppers, which Westerners are more familiar with and which sansho contains little of.

Sansho seed pods begin to take on shades of red as they mature through the season, before being harvested and dried. Finally, the bitter or otherwise flavorless seeds are discarded after being separated from the desirable outer hulls. What is left is the most ubiquitous form of sansho: kona sansho. The possible applications of kona sansho are essentially limited only by the imagination, but traditionally may be found in shichimi togarashi, a quintessential Japanese spice blend, in unagi and yakitori restaurants across Japan, and in toso, a spiced sake enjoyed in anticipation of the New Year. Returning to its taxology proves helpful here; approaching sansho as a citrus and not simply another pepper helps to explain why it has been matched as it has, as well inform future possibilities for it. Just as a squeeze of lemon helps to freshen and cut through the rich fattiness of proteins, ground kona sansho commonly is sprinkled over grilled eel, balancing its richness. And as chocolatiers have often matched orange with the floral qualities of cacao, they have begun to pair chocolate with sansho!

Stone-grinding kona sansho (Photo by Japan Hoppers)

While sansho may require some time and patience to be accepted into the Western palate, it is certainly deserving of it. Consider introducing it little by little and experiment with the range of its applications. While fresh mi sansho can be difficult to source outside of Japan, Asahi Imports does offer a ground and ready to use kona sansho which would be a fantastic option to begin your exploration of sansho with. Come visit us at the store and feel free to bring any sansho related questions you might have!

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