This is what's called a second dashi, "niban" means "second" in Japanese. This second dashi uses the ingredients from making the first Dashi (or ichiban dashi). Niban dashi is slightly mellower in flavor than ichiban dashi and is traditionally used in dishes where dashi is not the primary flavor. In miso soup, this niban dashi serves as the supporting role to the miso, showcasing the miso.
At home, I try to always make niban dashi because I use so much dashi in my cooking, and this simple extra step will double the output. If you're not going to use it right away, you can always freeze it and store it in your freezer. Ice cube trays work great for storing small quantities which can be used later add to many dishes.
- When you soak your konbu for the first dashi, try to remember to also soak additional konbu for this niban dashi. If not, no worries, just add it straight to the quart of water this time.
- Now add the konbu and katsuobushi from the first dashi you made into the water with the konbu. Bring to just below a simmer and leave it at that temperature for one hour. After an hour, add the fresh batch of katsuobushi, let steep for 30 seconds to one minute and strain.