Humans can aptly be described as opportunistic eaters to a certain degree. Our diet breadth is undoubtedly stunning. We ingest almost everything we encounter. Few things are immune to our virtually insatiable all-purpose stomachs. Not even kelp.
Kelp, seaweed, and algae are largely interchangeable, though some kelp is not seaweed but all seaweed is algae. It’s a bit of a tricky relationship, really. Now, obviously there are a plethora of different kelp varieties, and we are not so bold as to have tried ingesting them all. A particular type of kelp, however, has been quite popular for some time now to the point where it is cultivated in large quantities and holds commercial significance. I am, of course, referring to kombu (昆布), dashima (다시마), or hǎidài (海帶), which is a group of edible kelp species including saccharina japonica.
Kombu is not to be confused with nori (海苔). The two are different types of algae, brown and red, respectively, and are easily distinguished by their appearance and texture, especially when dried.
Kombu is eaten and used in the kitchen primarily in China, Japan and Korea, but it has spread, as different cuisines diffuse, across the globe. That said, in Japan, kombu is used to the fullest. It is a chief ingredient in dashi (だし), a classic Japanese soup stock (which is, amongst other things, the standard soup base for miso soup). While kombu is typically a foundational element in many dishes, it is eaten on its own prepared in a variety of methods: dried and seasoned, sliced and marinated, boiled to soften, raw, as a snack.
Kombu will carry a distinct white powdery residue, particularly prominent when dried, which is where a lot of the flavour supposedly comes from, and thus more white powder may imply better quality. The flavour of kombu typically described as similar to that of mushrooms, and not obnoxiously salty and fishy at all. Also, omitting the precise science of it, kombu is strongly associated with umami (旨味), a taste (best described as ‘savoury’) discovered by the Japanese in the early 1900s, and mono sodium glutamate (MSG). Overall, kombu (or some sort of substitute, powered or otherwise) is a staple in Japanese kitchens, and is marketed as a nutritious food item, high in dietary fiber, iodine, and other minerals.
A rather impressive fact is that kombu is speculated to date back to the time of the Jōmon, who are, put simply, prehistoric Japanese. What I find most interesting, however, is that it can also used medicinally to mitigate flatulence, indigestion and constipation, apparently. Who knew?