These are the apex of Katsuobushi, a special fermented style made from poached and dried skipjack tuna which is smoked for about two weeks, which then goes through a six-month(!) multi-stage process of fermentation and sun drying. Finally, the dried tuna cuts are ready to be sliced. This kind specially fermented bonito is also known as karebushi. 

This thick-shaved style is great for making a deeper, more nuanced and rounder umami-rich dashi. Remember to let the flakes steep for at least 20 minutes. The longer you steep, the more intense your dashi will get!

Karebushi has a softer, more sophisticated flavor, with less smokiness than its non-fermented counterpart. Typically, when Japanese chefs want more depth in aromatics and nuanced flavors, they go for karebushi. When they want more smoke and intensity, they'll go for the non-fermented katsuobushi. Want both depth and smoke? They'll use both! 

Made in Makurazaki, Kagoshima by Matoba Suisan.

Store at room temperature, away from direct sunlight. Keep refrigerated after opening for maximum freshness.