The flakes are thin, weigh next to nothing and have a very fishy smell.
To make the flakes, the tuna is first boiled, then smoked, then dried in the sun in blocks, then shaved into the flakes, packaged and shipped.
Purists say that the best flakes are those you do at home yourself, freshly shaving them as you need them from a piece of dried tuna.
The flakes are great treats for cats, too (seriously.)
Konakatsuo is powdered Bonito Tuna Flakes. It can be used as a seasoning or topping.
Kezurikatsuo are larger, thicker shavings.
Hanakatsuo are smaller, thinner, almost transparent shavings.
Cooking Tips
Kezurikatsuo Bonito Flakes can be used to make Dashi by simmering them in some plain water; you don’t boil the flakes in water for too long, though, or your dashi will be overly fishy tasting.
If you need a very fish-flavoured stock for other uses, even in Western cooking, you can make a quick fish stock with them — the longer you simmer them, the more pronounced the fish flavour.
You can use the Hanakatsuo flakes as a garnish on dishes, such as a sprinkle of flakes over cooked vegetables, tofu or soup. Very small packages (about 3 g) of them are intended for garnish use.
Equivalents
1/3 cup = .15 oz / 4 g
1/2 cup = .2 oz / 6 g
1 cup = .4 oz / 12 g
Language Notes
Tosa, in Kochi prefecture in Japan, was known for its shaved bonito, so any food item with the word “tosa” in it can be expected to have something to do with shaved bonito.