1. Put the herring on the chopping board, cut it from the tail along the back to the head with a knife, split the head, cut it into two pieces connected with the fish abdomen, dig out the internal organs and gills, cut off the teeth, scrape off the black membrane in the abdomen, and wipe off the abdominal cavity with a clean cloth.

2. Mix the refined salt and saltpetre evenly, and rub it all over the fish. Rub it twice more at the back bone, and stick a few holes in the thick meat on the back, so as to insert the salt and saltpetre and prevent mildew. Then put it into a vat (fish scales down) and press it with big stones. After 7 days, take it out, wash it with clear water and dry it in the sun for about 1 days.

3. Cut the dried fish into small pieces with a length of 1 cm and a width of 3.5 cm, and put them into a small earthen jar. Brewed wine, white sugar, Shaoxing wine and distiller's grains are mixed into juice, poured into the earthen jar to immerse the fish pieces, crossed with two pieces of bamboo, then sealed the jar mouth with clay, and marinated in the shade for four months.

4. before eating, put the dried fish into a pot, add the original marinade, sugar and Shaoxing wine until the fish is immersed, cover it, put it in a cage and steam it over high heat for about 1 hour until the fish turns bright red.

change the knife to a plate and pour the steamed juice. The old bittern from bad fish is filtered to remove impurities, disinfected at high temperature, put in a clean jar and sealed with clay, which will be used for the next year, with better quality.