Dashi: The root of Japanese cooking
I’ve been cooking a lot of Japanese food this year, in preparation for an upcoming trip to Japan, and time and again I’ve come back to one observation: dashi is the heart and soul of Japanese cooking.
Dashi is to Japanese cuisine what veal stock is to classic French cuisine, only more so. The most common type of dashi is made from water, a seaweed called kombu, and katsuo-bushi, or dried bonito flakes. Each of these ingredients can vary widely in type and quality, producing very different stocks. (Yes, this is even true of water. In fact, in some ways, the water is the most important element. More on that in a second.)
The one thing you should avoid doing is using powdered dashi, also known as dashi-no-moto. In some preparations, its flavour can be acceptable, but it will never shine. In soups, its flavour can be downright unpleasant. You wouldn’t use powdered bouillon in Western cooking, would you? I didn’t think so.
A good dashi has two characteristics: a subtle, smoky aroma from the bonito flakes, and a sledgehammer of umami from the kombu. That’s because kombu is extremely high in glutamic acid; in fact, when MSG was first isolated, it was derived from kombu.
This is where the water becomes important, though: it turns out that if your water has more than 60 parts per million of calcium, you won’t be able to extract the glutamic acid effectively from the kombu, which will leave you with an inferior dashi. Because I live in Guelph, which has notoriously hard water, I use demineralized water whenever I make dashi, and it makes a notably superior product.
How to make dashi
Once you track down the ingredients – and most Asian groceries, especially Japanese or Korean ones, should have them – dashi is dead simple to make. In fact, it’s faster and easier than Western meat stocks. Which is a good thing, since it doesn’t keep as long.
There are many approaches to making dashi; I use the approach described in Yoshihiro Murata’s book Kaiseki, which goes as follows:
Take 1.8 litres of soft water, a 30g. piece of kombu and 50g. of shaved bonito flakes. Wipe the kombu, then put it in a saucepan with the water. Heat to 60°C (140°F) and hold at that temperature for one hour. Remove the kombu, then raise the temperature to 80°C (176°F). Remove from the heat and add the bonito flakes. Once they’re soaked through, wait 10 seconds, then strain the stock through a coffee filter. Use immediately or refrigerate for up to three days. Dashi doesn’t freeze well.
How to use dashi
When making dashi-based soups, like the miso soup pictured up top, it’s important to remember never to let the dashi boil. Ideally, garnishes that require cooking (such as carrots) should be cooked in advance, then simply reheated in the dashi. Other dishes may call for you to reduce dashi by boiling, but in those cases, the delicate flavour is not as important, since they tend to be seasoned with soy sauce, mirin and other flavours as well.
Have you made dashi before? Or do you use powdered dashi?