Dashi made in fridge

Japanese swear by dashi, their base soup stock made from kelp and bonito flakes. When one eats a soup in Japan, it is clear why: umami is off the chart. So I always wanted to learn how to create that magic. I tried recipes from the web, and the result was OK, but not the real thing.

Until I finally had an obvious idea. I was in Tokyo, and I realized that I could ask locals how they made dashi! So brilliant and original, I could hardly believe myself. I even picked a really smart person, my colleague Ryoichi who has invented tons of things, so making dashi should be child play to him. He shocked me when he explained that the easiest and most reliable way to make dashi was to soak kelp in water in a fridge in two days, heat it up, and then pour it over bonito flakes that one packs into a coffee filter.

I politely promised to try this method and stayed quiet about my doubts. How wrong I was - the result is liquid umami that one can use for all sorts of things, usually even without adding any salt.

Procedure:

• Obtain kombu (dried kelp), and bonito flakes in a Japanese store.
• Take a plastic container. I use 1500ml. Add two small pieces of rinsed kombu, and fill with filtered water.
• Leave in a fridge for two days, or more, I have done up to 5 days. The kelp will expand dramatically and the water will draw goodness out of kelp.
• If you want a vegtarian dashi, you are done - use it in a few days. If you want to add bonito flakes, there is a little bit more to do:
• Pour the kelp water into a sauce pan, it will look like this.

• Start heating the water until it almost boils. If it boils the world does not end.
• Outfit a pour-over coffee dripper with a wet filter, and pack it with bonito flakes.

• Set the dripper over a jar that can hold all of the kelp water. Slowly pour the hot kelp water over bonito flakes, just like when making a pour-over coffee.

• When you are done, you have perfect dashi. 
• It keeps in the fridge for a few days.
• I am learning to start a new batch immediately when I made the previous one.

You can drink dashi, use it to make soup or sauces. I even use it to boil beans!