Dashi: steep, don't boil
Dashi is Japan's everyday stock, and it takes about 20 minutes. Kombu (dried kelp) is rich in glutamate, a savory amino acid. Katsuobushi (dried bonito flakes) adds inosinate, a savory nucleotide. Together they taste far stronger than either alone.
Warm the kombu slowly
Start kombu in cold water and warm it slowly. Lift it out just before the boil, or it turns slimy and bitter. Add the bonito off the heat, steep a minute or two, then strain. Don't press the flakes, which squeezes out cloudy, harsher liquid.
Test yourself
Questions from the interactive lesson, with the answer and the why.
Why does classic dashi use kombu and bonito together instead of a double amount of kombu?
Glutamate and inosinate boost each other's savory taste. Two different savory compounds taste stronger together than either alone.
True or false: Boiling kombu hard for 20 minutes pulls out more flavor, so it makes better dashi.
False. Hard boiling turns kombu slimy and bitter, while gentle warmth extracts clean glutamate.
What went wrong? You leave kombu in a rolling boil for 15 minutes. The dashi turns out slimy, bitter and heavy.
The kombu stayed in boiling water too long. A hard boil makes kombu slimy and bitter, so lift it out before the boil.
Fill the blank: Kombu is rich in ___, an amino acid that tastes savory.
Kombu is rich in glutamate, an amino acid that tastes savory. Glutamate is the savory amino acid that kombu releases into warm water.
You forgot the kombu and the pot is at a full boil. What's the best move?
Lift the kombu out, then add the bonito off the heat. This stops the damage and still adds the second savory compound.