1. Dashi and umami
Umami – a Japanese word roughly translating to “yummy” or a “pleasant savoury taste” was first coined in 1908 by Japanese chemist Kikunae Ikeda. Ikeda noted that this taste was apparent in tomatoes, cheese and meat, but was strongest in dashi, a staple Japanese broth commonly made from kombu and katsuoboshi (dried, smoked bonito or skipjack tuna). Scientifically, umami is comprised of three acids: Glutamic (found in kombu), Inosinic (found in katsuoboshi, or bonito flakes), and Disodium Succinic (found in shellfish). That umami was found to be the strongest in dashi is not at all surprising; a basic dashi broth already contains two thirds of the acids needed to form umami.
2. Commercial vs non-commercial dashi
Dashi often forms the backbone of many Japanese dishes, commonly being used to flavour donburi, miso soup, chawanmushi, and other simmered dishes. The brewing of dashi has traditionally been an exercise in taste and technique – since a basic dashi utilises only two ingredients, the ratio of ingredients to water, as well as the cooking time can vary widely depending on the seasonality and quality of ingredients, and ultimately relies on the chef’s expertise to consistently deliver a delicious dashi. However, many restaurants often rely on Hon dashi, a commercial quality dashi containing monosodium glutamate (or MSG) to add taste to their dishes. Compared to a dashi simmered using quality ingredients, such commercial grade dashi only add a salty flavour and no other nuances to the palette.
3. Dashi is unlike any other soup
Unlike French stock or Chinese gao tang which require endless hours of boiling, the cooking time involved in making dashi could be as short as 10 minutes. The kombu has to be taken out right before the water reaches boiling point – this prevents the broth from becoming slimy and bitter, or even too overpowering in flavour. Some restaurants choose a “cold soaking” method, whereby the kombu is soaked in cold water for a day, before it is removed the following day and the liquid simmered with a new batch of kombu. This ensures a concentration of flavour, and the gentle heat causes any impurities to rise to the surface, which can then be skimmed off.
4. Ichiban and Niban dashi
When the kombu is removed, katsuoboshi is added to the broth to steep momentarily before the liquid is strained to yield ichiban dashi – the first broth. This clear broth is usually the main dish in a multi-course kaiseki meal. A good ichiban dashi should have a bright and nuanced flavour, with an umami depth from the katsuoboshi. Niban dashi – the second broth – is made by adding water to the ingredients strained from ichiban dashi, and katsuoboshi with chi ai or bloodlines – stripes of dark, blood-rich muscles that run down the spine of the fish. Katsuoboshi with chi ai is considered second tier katsuoboshi, but it helps to pack more flavour into the niban dashi.
5. Varying your dashi
To the niban dashi, different seafood can be added according to the requirements of the dish that the dashi will be used in. Jako – dried baby sardines – can be added to make jako dashi. As jako has a distinctively fishy smell, jako dashi is better used in non-seafood based dishes such as miso soup and kitsune udon. Saba or mackerel can also be used to make saba dashi. Its rather astringent taste goes well with soy sauce, making saba dashi the choice dashi for soba noodle dipping sauce. Urume – dried and smoked sardine – is similar in taste to saba dashi, but has a slightly smoky aroma. Its light and subtle flavour makes it suitable for simmered dishes, or for udon and soba noodle dipping sauce.
Apart from adding other ingredients to your niban dashi, ingredients can also be subtracted from the dashi. Kombu dashi – made only from kombu – is used when dishes contain mainly fish or seafood, as katsuoboshi will overpower the flavours of the seafood. This dashi is also suitable for vegetarians or vegans.
6. The quality of your ingredients matters
The quality of kombu and katsuoboshi are vital to packing in that umami flavour into any dashi. Ideally, aged kombu and katsuoboshi are preferred . The drying process for both ingredients can take several years, with a longer fermentation process creating a complexity in flavour that only time can.
On every last Saturday of the month, NAMI Restaurant & Bar holds an afternoon dashi appreciation class ($118 per person) bringing guests through the art of crafting and appreciating dashi. Guests can taste and compare the flavours, aromas and colours of different types of dashi. The class will be followed by an exquisite four-course set lunch. A new dashi menu ($180 per person) is also available, showcasing the dashi made in NAMI in a 7-course meal of specially curated dishes, such as Miyazaki beef loin, Hamaguri clam soup with chicken, and fruit cocktail with plum vinegar jelly stock.
22 Orange Grove Road, Tower Wing, Singapore 258350. Tel: +65 6213 4398. Website here