Dashi is an essential broth base for most Japanese dishes and can be purchased in most Asian Grocery stores. For those of you who want to do it from scratch there are several recipes out there, but I find this one is easiest. This recipe uses Konbu (also spelled Kombu). This is a good vegetarian broth and enhances the subtle flavour of Japanese cuisine. It is also a bit friendlier to the western chef than katsubuoshi, which is made from dried fish flakes and can b very aromatic.
Dashi should be pale gold in color and smell like the sea. Keep Dashi covered and refrigerated when not in use. Dashi will keep for up to 14 days. The stock will smell sour when it has gone off.
Dashi can also be made cold by soaking the konbu in water for 1-2 hours.
This was exactly what I needed to make my miso soup shine. Perfect! It will cook down a little though when it simmers, so be sure to add extra water. - 13 Nov 2010 (Review from Allrecipes US | Canada)
I use this recipe for dashi every time I make a dish that requires plain water. Seaweed is high in nutrents needed, that are not common in American diets. I chop the bulk Kombu into beef stew where it adds a uncommonly good flavor. When using any type of seaweed, I do not add salt to the dish as it cooks. - 13 Mar 2013 (Review from Allrecipes US | Canada)