It is the basis of most Japanese traditional dishes if not all, miso soups for the most known example. Dashi is typically made with three simple ingredients – bonito fish flakes (katsuobushi), dried kelp (kombu) and water.
Katsuobushi is made of bonito fish fillets that have been dried and smoked until they are as hard as a piece of wood. The bonito is then shaved into flakes.
Katsuoboshi and kombu are both known to give umami, which can be described as pleasant savory taste with a long lasting, mouthwatering sensation over the tongue.
Umami represents the taste of the amino acid L-glutamate and 5’ribonucleotides such as guanosine and inosine monophosphates, most notably found in fish, cured meats, mushrooms, vegetables, green tea, and fermented products, e.g., cheeses, soy sauce. With dashi, L-glutamate comes from kombu and inosine from katsuobushi.
Interestingly, many of us first encounter umami in breast milk, which contains roughly the same amount of umami as broths.
We make our soup stock slowly with natural ingredients. We add to katsuobushi and kombu dried flakes of bullet tuna (soda katsuo) and mackerel (saba) for milder and richer tastes.