The creation of Katsuobushi
The process of making katsuobushi begins by filleting fresh tuna (skipjack) into three pieces called kame bushi (“turtle cubes”). The large piece is then divided into two halves — called mebushi (belly) and obushi (back) — creating honbushi (“main block”). The cubes are placed in a woven tray in hot water, carefully arranged to ensure uniform flavor in the final product, and simmered for 60 to 90 minutes in a step called shajuku, sealed in inosinate. The skin and bones are then removed. The blocks were called namaribushi at this time. The next step is baikan (“smoke drying”). Namaribushi undergoes a lengthy smoking process to remove water content and prevent spoilage. After the first round of baikan, cracks and cavities are repaired using a paste made from the head and nakaochi (tuna scraping), followed by more than a dozen more rounds of baikan to remove more water, killing harmful bacteria and prevent them from taking over. Holds and prevents oxidation.
