It’s the foundation stone of Japanese food and cuisine, an essential element upon which layers of flavour, aroma and texture are laid. But in most western kitchens dashi remains an enigma.
In simple terms, dashi is a stock. A flavoured liquid that’s at the heart of familiar recipes such as miso soup. Rather like the stocks of French cooking, it is the source of hundreds of dishes, a catalyst for an explosion of flavours, both bold and subtle. But where French stocks are notorious for taking ages to prepare - involving much roasting of bones and vegetables, and hours of boiling with herbs - dashi can take just ten minutes.
ICHIBAN, THE PRIMARY DASHI
The most commonly used dashi is known as ichiban or primary dashi. It is made with just three ingredients: cold water, kombu and katsuobushi. Kombu is dried Japanese kelp, which imparts savoury umami hints that bring out the flavours of other ingredients. Katsuobushi is bonito (or skipjack tuna) which has been dried, smoked and fermented, and then shaved thinly. It’s also umami-rich and serves to enhance other flavours. Both ingredients can be widely found in Asian stores in western countries or ordered online.
To make ichiban dashi, first you must heat the kombu and water steadily in a saucepan. The kombu should be removed from the water a moment before it comes to the boil. Be careful to skim off any scum on the water. The stock is then taken off the heat and katsuobushi flakes are added. Renowned Japanese chef Nobu Matsuhisa recommends waiting until the flakes have sunk to the bottom of the pan before straining the dashi through a fine sieve lined with cheesecloth or paper towels.
And that’s it. No bone roasting. And no misting up your kitchen windows with hours of boiling. Ichiban dashi has a rich golden colour and a refined yet bold and smoky umami flavour, which is ideal for making suimono or clear soups, noodles and dipping sauces. It’s to be used anywhere you want the dashi to make an impact. The leftover kombu and katsuobushi can be used again to make niban or secondary dashi, by adding cold water and simmering for a few minutes. Niban dashi is lighter in appearance and flavour than ichiban dashi, and is used to make nimono or simmered dishes.
SOME FISHY TIPS
If you’re making a fish nimono however, it’s best to use a kombu dashi made without katsuobushi, to avoid overpowering the dish with fishy flavours. This can be made by gently simmering kombu in water, although some chefs merely pass the kombu through very hot water for a few moments to achieve an extremely subtle flavour that allows the flavour of fish to shine through.
While the quality of kombu and katsuobushi plays a huge part in the flavour of dashi, so does the quality of the water. Some purists say hard water makes it difficult to extract the required amount of glutamic acid from the kombu to achieve an umami flavour. Only soft water will do, so if you live in a hard water area, hard luck.
There are many other varieties of dashi, some involving dried shiitake mushrooms or dried sardines. But as dashi’s stock has grown in the west, more chefs are are beginning to use it in their kitchens, in increasingly creative ways.
THE CHEFS' TOUCH FOR A GOURMET DASHI
The French chef Jean-Georges Vongerichten has been known to combine dashi with mayonnaise. Heston Blumenthalhas experimented with shellfish instead of katsuobushi in his dashi. And the Korean-American chef David Chang of Momofuku fame has combined kombu with apple juice to make apple dashi.
But perhaps Chang’s best-known dashi variation is bacon dashi. In goes the kombu, but out goes the katsuobushi in favour of good old smoked bacon. His bacon of choice is the American brand Benton’s, which is simmered alongside the kombu for 30 minutes at no more than 60 degrees Celsius.
Chang’s bacon dashi brings wonderful smoky umami-ness to a whole host of recipes, from a simple cabbage soup, to soba noodles with shiitake mushrooms, tofu and spring onions. Or you can drink it neat like tea. Once you know the secrets of dashi, anything is possible.