For me, katsuobushi has always been synonymous with the flavors of Japan. There is no substitute for it. Over the years as my Japanese cuisine knowledge has expanded, I have come to understand and taste the differences between the various varieties of konbu and shoyu and how and when to use them. Yet, how to use karebushi (fermented) versus arabushi (non-fermented) katsuobushi was still elusive to me until our April 2022 trip to Japan. Prior to the trip, I had been told the main difference was that karebushi had more umami compared to arabushi, but when I tasted them side-by-side the difference seemed very slight. And I still needed to answer the question “How and when do you use each of them?” So I set off to Japan to get some help answering my katsuobushi questions
I was incredibly fortunate to learn from the best of the best when it comes to dashi culture: Doi-san from Konbu Doi and Uneno-san from Uneno. My first lesson of the trip was taught by Doi-san during a wonderful dinner at a Michelin starred restaurant in Osaka. This lesson in katsuobushi “theory” involved Doi-san comparing and contrasting both types and scribbling everything down on small pieces of paper. These have become a treasure to me. I am a very visual learner, so this helped tremendously. The second lesson took place in Uneno-san’s tasting kitchen in Kyoto. This lesson was more practical in that Uneno always had us actually taste dashi with him. Over the years we have had at least 5 of these tastings with him. Each time I walk away full of new knowledge and great appreciation in the fact that I have some of the best mentors ever.
Before we dig into what I learned from both of them, let’s first quickly revisit how katsuobushi is made. To start, raw skipjack tuna loins are cleaned and poached. Then they are smoked for approximately 2 weeks. At this point they are known as Arabushi. If you then take these arabushi and put them repeatedly through a cycle of fermentation and drying, after about 6 months, they become karebushi. To dig a bit deeper into the production process, please see your blog post about visiting Matoba Suisan here.
As I learned and witnessed with Doi-san and Uneno-san, when you are using arabushi you are getting the intense, almost wild flavor from the outside of the loin, so it produces a strong taste. On the other hand, because the outside has been fermented, karebushi has a softer, more sophisticated flavor with less smokiness. It was then explained to me the arabushi produces stronger flavor while karebushi produces more aroma. Bingo, the lightbulb went off and I started to understand much better. Generally speaking, dishes like ramen, soba and udon require the strong flavor of arabushi, but karebushi is great with nimomo (simmered dishes) or chawanmushi (steamed dishes) where you desire more of an aroma. Uneno-san explained when Japanese chefs want to have strong flavor and aroma, they use both! Mind blown…
With these lessons under my belt, it was now time for another, and our good friend, sesame producer extraordinaire and exporter, Takehiro had something very special planned. A private dinner at his friend and master chef Takaso Kakihara’s restaurant Ajigen. Kakihara-san made us a dinner utilizing both styles of katsuobushi, giving us this perfect opportunity to see the differences displayed in a practical way. It started like most formal Japanese meals with some small bites then right into 2 nimono (simmered) dishes that were the same, but each were prepared using dashi made with a different katsuobushi. The dish was a dashi broth with Hamo, a beautifully light-tasting whitefish that takes tremendous skill to prepare, with some myoga and onion. First up was the karebushi dashi which filled your olfactory sense with aroma and it played perfectly with all the ingredients. It was stellar. Second was the arabushi dashi which after tasting the first one made with karebushi, was too strong for the delicate Hamo. To be honest, maybe if I was served that dish when we were not doing a side-by-side tasting, I might have thought it great, but not mind blowing. Such a useful way to present these differences
I am grateful for the time Doi-san, Uneno-san and Kakihara-san spent with me and their generosity in sharing their knowledge. I know I am still at the beginning of my katsuobushi journey, but I feel like I am much further down the path than I was before these lessons!
In your own home, please know that you really can’t go wrong with either style of katsuobushi. There really is no right or wrong. Cooking is subjective and takes repetition to really hone your skills. So if you are like me, you will start to take these nuggets of katsuobushi wisdom passed along by these wonderful Japanese masters and implement them along your own katsuobishi journey. And remember the golden rule: always make sure to have fun cooking along the way…