All About Japanese Dashi

Dashi (だし汁, dashi-jiru) is a cornerstone of Japanese cooking. It's like "starting with a roux" in a Southern-US cookbook. Dashi appears as an ingredient in dozens of Japanese menu items, from miso soup to broth for udon noodles.

Purist chefs will insist on cooking up a fresh batch of dashi as a preliminary step for other dishes. Fresh dashi involves boiling squares of dried konbu kelp and dried fish shavings in water--the resulting, strained stock is the dashi, which you either use in your next recipe or store for future cooking. Fresh dashi keeps well in the fridge for a few days.

(The blog Just One Cookbook has a good, simple recipe for making your own dashi, and it also covers detailed instructions on how to use "instant" dashi, which we'll talk about next.)

Deus ex machina. Now our cooking can continue.

Since I don't have anyone else at home to impress with my cooking, following a recipe in order to make an ingredient for another recipe seems like a fairly prohibitive time investment for the average weeknight dinner. And even though dashi stores well in the fridge, I usually don't know at the beginning of a week if I'll be cooking consistently enough to use up a large batch. Fortunately, for people like me there's a modern alternative:

Powdered dashi mix (だしの素, dashi no moto) is a cheap, fast way to make dashi. A dozen brands of this stuff will be on sale at any well-stocked Japanese supermarket, each with slightly differing flavors.

Every brand will describe its particular powder-to-water ratio, but usually the packets are 8 grams and mix into about 1,000 ml of water. You can adjust the strength of the flavor by using more or less dashi or water.

Although I call it "powdered," dashi mix is really more granular, almost like a pellet. In fact, dashi mix looks and smells disturbingly similar to the pellets I used to feed my pet Betta. The similarity put me off at first, but now I just hold my breath while I mix it in: The flavor in the final recipe is worth the initial fishy unpleasantness.

For chefs looking for a halfway point between cooking fresh dashi (and thus always keeping konbu and katsuo-bushi on hand) and using the "fish food," consider dashi packets (だしパック, dashi pakku), which are tea bags with kelp and fish shavings inside. You bring the packet to a boil in water, just like tea, and when you pull the bag out you're left with a tasty batch of dashi in the pot.

Finally, for situations when even preparing dashi from powdered mix is not desirable, bottled dashi and single serving packets (of liquid dashi) are often available in supermarkets alongside fresh, ready-to-eat packages of udon noodles. Once open, the bottles will expire as quickly as a freshly cooked batch of dashi, and the single serve packets will always be marked for expiration after just a few days. Some, but not all, bottled brands may keep for a few months and not require refrigeration as long as they are sealed. Always check the expiration date to be safe.