Dried squid and kelp are cut into fine threads, shredded carrot goes in with them, and the lot is combined with herring roe and steeped in soy sauce, sake and sugar. Left for a day or two the kelp releases its viscosity and the whole thing draws together. Lift a chopstick and it comes up in long strands. There is no way to hurry that stage; it simply has to sit.

Matsumae, at the southern tip of Hokkaido, was a major producer of both dried squid and kelp. Soy sauce began arriving reliably on the northern trading ships in the Kansei era, around the turn of the nineteenth century, and the pickle appears to date from about then. During the decades when the herring runs off this coast were enormous, fishing households made it as a store to get through the winter.

Herring roe has since become expensive. Most matsumae-zuke sold today is squid and kelp with very little roe in it, which means the original version is now the luxury one.

A shop in Hakodate turned it into a packaged product in 1937 and it went out across the country from there. A thing made in a fishing household to get through a winter, ending up in a souvenir box at the airport.