Dashi & Katsuobushi

Dashi is the foundation of Japanese cuisine, the basic stock that infuses Japanese dishes with its distinctive, savory, umami-flavor. There are a number of dashi types, but the classic one is prepared from kombu and katsuobushi.


Katsuobushi, dried, fermented, young or old depending on the budget. The umami of Katsuobushi comes from the process imposed by smoking and fermenting the skip Jack tuna. It is used to give a subtle flavor with konbu, a Japanese seaweed.


When working in my Japanese kitchen, I often, if not daily, make Dashi. I use the finest Konbu and Katsuobushi, and probably over spend on buying seaweeds. I have posted on Rausu kombu which is outstanding although it is amongst the most expensive the world over: http://www.kurakonusa.com/kombu/history. In fact the finest Kombu never reaches the public and is traded and distributed to the finest chefs throughout Japan.

Dashi preparation is a process of extraction and infusion of flavors. You extract the flavors of kombu by steeping or heating in water, then infuse the liquid with katsuobushi. Classically, there are two versions of the dashi, “ichiban dashi” is a delicate stock meant for clear soups (suimono), and “niban dashi” is used for all-purpose stock to cook with. But often I use ichiban as I prefer the first stock.

I use different Dashi in just about for everything I cook. There are a few ways to extract the flavor by temperature and time as they both influence extraction. Soft soak the kombu overnight in the fridge after gently warming the water under 30+- degrees centigrade. There are other ways to deal with the making dashi and using Kombu, i.e. vacuum the kombu in a bag and follow the same process. Obviously consistent temperatures help to gain better results.

1 litre water
60 grams kombu
2-3 large handfuls of katsuobushi
10 grams niboshi

If you are starting with dry konbu, add the water and kombu to a pot and let it sit at room temperature for 30 minutes. Place the pot over medium heat and simmer until approximately sixty degrees centigrade. Remove the kombu and set aside. This steeping and heating process will extract the maximum flavor from the kombu and by cooling it slowly you’ll impart the glutamate. Use a kitchen thermometer for more precision.

Then remove the kombu and bring the water to 70 degrees centigrade, turn off the heat. If the water is too hot when you add the Katsuobushi you’ll release its impurities and possibly change or damage the flavor. You want the temperature to be about 70+- degrees centigrade.