Noodles and Rice

Ingredient Spotlight: Katsuo-Bushi

by Stef on May 3rd, 2006

And here it is, katsuo-bushi, the indispensable ingredient that gives life to Japanese dishes seasoned with or cooked in dashi.

Katsuo-bushi is made from the tuna-like skipjack (scientific name Katsuwonus pelamis), or bonito, a member of the mackerel family. The Japanese have been steaming/boiling and drying this fish since the fifteenth century and using it the way we do today. After processing, the fish looks like a piece of wood, and can then be shaved into flakes with the use of a katsuo-kezuri-ki, or “bonito shaver”. This is a bladed wooden utensil in the shape of a box, similar to a woodworking hand plane, but with a drawer to catch the flakes. The flakes themselves are called hana-katsuo, or kezuri-bushi. To keep it fresh, store in an airtight container.

Katsuo-bushi comes in several forms, though the most common one is the packaged flakes as in the picture above. A similar product called ito-kezuri-katsuo has a finer, almost thread-like texture, and is often used as a garnish. Atsu-kezuri, which is a thicker chunk of bonito, is another one.

The process of preserving bonito is both fascinating and remarkable. In the book Memories of Silk and Straw: A Self-Portrait of Small-Town Japan, the author, Junichi Saga, has compiled her patients’ stories of pre-war Japan. One that struck me in particular was Josuke Kikuchi’s account of his grandparents’ katsuo-bushi-making business. He describes how the best bonitos were caught from 72°F waters, and that those caught in water only a few degrees cooler were considered inferior. Apparently, the ones in cooler water develop a lot of fat and after processing and drying, they cracked when you tried to shave them. He goes on to describe the “team members” responsible for preparing the fish; each had his own task, with the fish cutter naturally needing to be the most skilled at his job. Interestingly, Kikuchi says that they boiled the fish, as opposed to steaming as it’s usually described in today’s cookbooks. Only soft springwater was good enough to use as the boiling liquid. The women would then take the fishbones out using tweezers. After this, the fish pieces were dried slowly over a pinewood fire, the level of heat being carefully controlled to prevent from overcooking the fish. A must read if you enjoy stories that involve the foods of long ago.

Harold McGee, a.k.a. The Curious Cook, also details the process in his book On Food and Cooking, although there are some differences from the Kikuchi account, such as the boiling in salt water as opposed to springwater, the removal of skin (which Kikuchi claims wasn’t done, to prevent sneaky merchants from selling pinewood as dried bonito), and the smoking over hardwood as opposed to soft. McGee, of course, goes further to explain the chemistry behind all this, listing all the enzymes, acids, peptides and phenolic compounds that result from the preservation process and contribute to making the finished product what it is.

All that to say that what you have in your hands when you make a pot of dashi using bonito flakes is something that needs to be treated with the care and respect it deserves. In return, we are rewarded with the same gastronomic pleasures that those long-ago fishermen and cooks enjoyed in every pot of dashi-flavored soup.

Related Stories

Katsuo Bushi
Katsuo fish stock
Katsuo Tataki
Dashi - basic Japanese Stock
Ingredient Spotlight: Pandan

POSTED IN: General : Asian Food / Cuisine, Ingredient Spotlight