Jappa is Tsugaru dialect for zappa, meaning the things you throw away. Applied to a cod it means the head, the bones, the skin, the guts. The soup is named after the discards, which is a blunt way to name a dish that people wait all year for.

All of it goes into the pot with daikon, carrot, and scallion, seasoned with miso. The head is split lengthwise, the backbone cut into manageable lengths, the innards washed carefully. At the end the liver is broken up and stirred through, and the broth thickens and turns rich. If fresh milt is available it goes in too.

Cod is the toshitori-zakana in Tsugaru, the fish that marks the turn of the year, and there is a local expression, tara shogatsu, cod new year. Households bought a whole large fish. Once the fillets were taken off for other dishes, what remained was the jappa.

So the name records an attitude that the cooking contradicts. Nothing here is treated as waste. The parts called rubbish make the broth that gets a household through a Tsugaru January, and the fillet, the part carrying the market value, is not what anyone in the room remembers afterward. I have been turning that inversion over ever since I heard the word explained.