This method of preparation had evolved by the Japanese occupation era into a meticulous process: After buying grey mullet at the market, the ovaries would be removed. After washing off the blood, these were then pickled in salt. The pickled product was removed from the salt, pressed flat, cut into shapes, and dried, thus completing the process.
日據時代，鹽漬加工法逐漸發展成一套精緻製程：自魚市場買來烏魚後，先將卵巢取下，去汙血後，以鹽醃漬、再脫鹽、壓平後整形、烘乾，始大功告成。