Dashi (wikipedia definition) is a type of Japanese soup stock; one of the most well-known uses of dashi is as the base that you add miso paste to make miso soup, however dashi is also used in many other applications in Japanese cooking, similar to how French cooking uses stock.
Dashi is extremely easy and quick to make. All you need to do is measure out ingredients, boil water, and strain. It is made from just three ingredients: konbu (giant kelp), katsuobushi (dried bonito flakes), and water. Quantities for these ingredients are given in the recipe below; however once you have made dashi a few times, you can eyeball the quantities since it isn’t necessary to use exact quantities. In fact, if you compare various recipes for dashi, you’ll notice that they often differ from each other in the amounts and ratios of konbu and bonito flakes used–I’ve seen recipes which use nearly twice as much konbu and bonito flakes and ones that use only half as much as my recipe below; you can adjust the amount you use depending on the strength of the broth that you’d like.
This is called primary dashi since it is the first extraction from the kelp and bonito. You can reserve the discarded bonito flakes and kelp for secondary dashi (recipe not listed here, but it is in Shizuo Tsuji’s book) if you like, though secondary dashi should only be used for as a base for thick soups or simmering foods or things like that since it will be much weaker and it will not have as pure of a flavor.
Vegetarian kelp broth, called konbu dashi, (which can be used as a vegetarian replacement for dashi) can be made by following the steps to extract the kelp flavor and and stopping just before the bonito is added. Kelp broth can also be used as a replacement for vegetable both in non-Japanese dishes; it helps to give the dish umami.
Good quality kombu will be covered on the surface with a fine white powdery substance. Don’t wash the white powder off of the konbu; it is part of what becomes the flavor the stock. Most kombu today is cleaned before being sold, so it is isn’t necessary to wipe it and can be used as is, unless you can see visible dirt on it. (If you do need to wipe it, be careful to not wipe off much of the white powder.) Konbu contributes glutamic acid to the stock, which is responsible for umami (wikipedia). Soaking it in water overnight helps to extract the most flavor; however if you are pressed for time, you can extract sufficient flavor by skipping the soaking step and placing the kelp in water that you slowly bring to a boil. The kelp is removed just before the water starts to boil — sufficient flavor has been extracted at this point. If your unsure you can test the kelp by inserting a fingernail into the fleshiest part of the kelp; if it is soft, then sufficient flavor has been extracted, otherwise return the kelp to the pot–keep the pot from boiling by adding 1/4 cup cold water; the kelp should be soft in about 1 to 2 additional minutes.
Fresh, good quality pre-shaved katsuobushi will be fluffy and yellowish-beige colored with a hint of blush pink. Konbu stores well over long periods of time, however bonito flakes lose flavor once the package is opened so they should be used up soon after the package is opened.
Since dashi keeps in the fridge for several days, I find it easiest to make a day before I first need it (since that makes one less thing to do when I’m preparing dinner), store it in the refrigerator, and then over the next few days I make other dishes which need dashi until it is used up. The dashi maintains its quality in the refrigerator — I even find that it is best on the second day since its fragrance and the smokiness seems to increase on the second day. If it is inconvenient for you to cook several Japanese dishes within a few days, dashi can be frozen for longer term storage, however freezing will cause a loss in quality — the smokiness imparted by the bonito flakes and other delicate flavors diminishes. But frozen dashi is suitable for cooking especially in recipes that only use a few tablespoons and it is superior to “instant” dashi mixes which often have preservatives. Miso or dashi based soups are best when made with fresh dashi though frozen can be used in a pinch. It is especially convenient to use an ice cube tray to freeze the dashi into small cubes, since many Japanese recipes call for a small amount of dashi . This makes it easy to melt a few ice cubes when needed. To defrost, gently heat until it melts or allow to defrost in the refrigerator.
Source: Based on “Fish Stock Preparation (Dashi)” from “The Sushi Experience” by Hiroko Shimbo and “Primary Dashi” from “Japanese Cooking: A Simple Art” by Shizuo Tsuji.
- 1 quart (4 cups) cold water
- 15 grams (1/2 oz) to 30 g (about 1 oz) konbu (kelp, sometimes also spelled as kombu)
- 20 grams (2/3 oz or 2 cups lightly packed) to 30 g (1 oz) katsuobushi (dried bonito flakes). Larger quantities of katsuobushi will make a stronger, smokier broth. If you want a light, not very smokey broth, then you can use 10 g katsuobushi.
(Optional) To extra the most flavor from the konbu, soak the konbu in 1 quart of cold water overnight (about 10 hours).
If the konbu hasn’t been soaked, add it to a pot with the water. Slowly bring the kelp and its soaking water to a boil, uncovered, so that it reaches the boiling point in about 10 minutes. Remove the kelp just before the water boils; kelp emits a strong odor if boiled that will overpower the stock. This stock is what is called konbu dashi (kelp stock) and can be used in vegetarian or vegan recipes as a replacement for dashi.
To turn the konbu dashi into dashi, allow the water to come to a boil, and then add the bonito fish flakes. Do not stir since stirring the bonito flakes will cloud the stock. Count 10 seconds, and then turn off the heat. The fish flakes should start to sink almost immediately though they may not sink all the way to the bottom. Let the stock rest with the fish flakes about 2 minutes and no more than 3 or 4 minutes. During this time remove any foam or scum that rises since it can effect the flavor. Line a fine meshed strainer with paper towels. Gently dampen the paper towels, without dislodging them, using a thin stream of water from the sink facet so that the paper towels will stay put. Put the strainer over a large pot or bowl and immediately pour the dashi through the paper towel lined strainer. Don’t squeeze, stir, or press the bonito flakes since this will cloud the stock. Remove the bonito flakes promptly; if the bonito flakes boil or soak in the stock for more than a couple of minutes, then the stock will become too strong, bitter, and “fishy” tasting and isn’t suitable for use in clear soups (though it can be used as a base for thick soups, in simmered foods, etc).
The dashi should be nearly clear; the paper towels should have filtered most of the fine sediment. It is okay for a small amount of particles to remain, but if you’d like to remove more, then let the dashi sit undisturbed for at least 10 minutes. The fine particles will fall to the bottom. Spoon all of the dashi from the top of the bowl into a clean bowl, being careful to disturb the liquid as little as possible (so that you don’t raise up the sediment), except for the few tablespoons of dashi at the bottom with lots of sediment. Discard the sediment filled remainder of dashi.
If you want an extra smokey broth, then you can either use thicker katsuobushi flakes, or once the dashi is cool, you can reheat it to a simmer, and immerse another few handfuls of katsuobushi flakes and strain.
Dashi can be refrigerated for up to four days tightly covered. Sediment at the bottom of the broth is not a sign of the broth going bad–it is just bonito particles that didn’t get strained out. The dashi is spoiled if any it has any one of these signs:
- it has a sweet (rather than smokey smell)
- a film has formed on the surface or edges
- if the consistency becomes sticky when pouring.
Variation: Dried shiitake stems can be used to infuse liquids with mushroom flavor. Don’t throw the stems away when you use the caps in other recipes; snap off the dry stems and save them in the same bag or container used to store dried shiitakes. To make mushroom flavored dashi broth, add a few dried shiitake stems to the water when you soak the konbu. The most flavor will be extracted if the stems soak overnight, but even a quick 30 minute soak will extract some flavor. Leave the stems in the water when you heat up the liquid, and strain the stems out with the shaved bonito flakes.