Kombu is a kelp used in most Japanese cuisines. It is rarely eaten alone except in Okinawan cuisine, but used to enhance the flavors of fish.
How Kombu is used in Japanese cuisine:
- One of the three main ingredients needed to make dashi, a soup stock. Kombu dashi is made by putting either whole dried or powdered kombu in cold water and heating it to near-boiling. The softened kombu is commonly eaten after cooking or is sliced and used to make tsukudani, a dish that is simmered in soy sauce and mirin.
- Pickled with sweet-and-sour flavoring, cut into small strips about 5 or 6 cm long and 2 cm wide. These are often eaten as a snack with green tea.
- Included when cooking beans, to add nutrients and improve their digestibility.
- Used to prepare a seasoning for rice to be made into sushi.
Kombu is always simmered to brew the flavors. It is important to place it in cold water and then heat it to a simmering temperature. Once the water starts simmering, then it is discarded after 30 sec or so. Not much time is needed for brewing since it can start to release strong kelp flavors if done too long.
Kombu is also the main ingredient used to extract mono-sodium glutamate or MSG. Only small amounts of MSG can be extracted per piece, but natural levels of the compound make the food taste the best, and artificially extracted salts should not be used to flavor dishes for it can alter the taste.
The mineral content of the kombu matches well with most sea foods, and can not be ignored when cooking Japanese food. It is first dried before sold.