What is in eel sauce?

Question

I've always love eating this dark eel sauce that goes with eel rolls at our favorite sushi restaurants. It's got a dark color it's sweet, a little salty, and slightly savory.

What is in eel sauce? What makes it sweet and so concentrated with flavor? Also, why is it called eel sauce?

Answer

sweet -> sugar+mirin (rice wine vinegar), salt -> soy, savory-> soy+mirin+eel bones. At home, you probably won't be able to manage eel bones boiled down into stock. Ignoring that, it's all a matter of mix and reduce. Sugar+soy+mirin, reduce to 1/3, revel in the joy of caramel and salt and sharpness.

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