Katsuobushi

Katsuobushi, also called bonito flakes, is a traditional Japanese ingredient made from skipjack tuna (katsuo, Katsuwonus pelamis). The name literally means "bonito shaved." It is produced through a lengthy curing process that yields a hard, wood-like block from which very thin shavings are produced.

The typical production involves gutting the fish, boiling it briefly, and then smoking it repeatedly for several days or weeks. After smoking, the fish is dried until it becomes extremely hard. In traditional methods a mold culture, often Aspergillus glaucus, is introduced to ferment and further stabilize the block before the final drying. The finished product may be sold as large blocks or as pre-shaved flakes.

Katsuobushi is commonly sold as kezuribushi, shaved into paper-thin flakes, or in larger blocks for home shaving. The flakes are a fundamental component of dashi, the base stock for many Japanese dishes, usually prepared with kombu (kombu dashi). They are also widely used as a garnish on foods such as takoyaki, okonomiyaki, and tofu.

Flavor and aroma: katsuobushi provides a strong umami flavor with smoky, savory notes, due to compounds formed during curing. It is highly shelf-stable because of its very low moisture content.

Storage: Keep in a cool, dry place; once opened, store in an airtight container. Shaved flakes should be used while fresh for optimal aroma, though the product remains long-lasting when properly stored.