Kombu

About

What is kombu and how is it used in Japanese cooking? Kombu is an edible kelp harvested mostly around Hokkaido, where cold water and long growing seasons produce thick, flavourful fronds. Once cut, it’s dried, pressed and sometimes aged so the taste deepens and concentrates. What makes kombu kelp distinctive is its glutamate content. In 1908, Japanese chemist Kikunae Ikeda was studying why kombu dashi tasted so satisfying. He isolated glutamic acid as the compound responsible and named the sensation umami – a fifth taste alongside sweet, sour, salty and bitter. Kombu remains one of the richest natural sources of glutamate, which is why a single strip can turn plain water into stock with genuine depth. The white powdery coating you’ll often see on dried kombu is mannitol, a natural sugar. It carries flavour and should be left on. Wipe the surface lightly with a damp cloth if needed, but don’t wash it under running water – you’d rinse away the very thing that gives the kelp its taste. Types of kombu Several varieties of Japanese kombu are harvested in Hokkaido, each with a different character. They’re broadly interchangeable for home cooking, but choosing the right one for a specific dish can make a noticeable difference. Rishiri kombu produces a clear, refined dashi with a clean savoury edge and very little colour. It’s prized in Kyoto-style cooking where the broth needs to be transparent and understated, letting other ingredients speak. We stock Rishiri wild kombu harvested from open water. Ma kombu is the most widely used variety. Thick, wide and light brown, it yields a slightly sweet, full-bodied broth and is versatile enough for dashi, simmered dishes, hot pot and tsukudani (kelp simmered in soy sauce and mirin). Our Ma kombu is available in large sheets, useful for making stock in volume or wrapping ingredients before cooking. Hidaka kombu is softer in texture and cooks down more easily than other varieties, which makes it a good choice if you want to eat the k