I promised to tell you how to make the perfect ichiban dashi – the basic Japanese ‘stock’ made from dried konbu seaweed, katsuobushi flakes and water.

(I may wear funny hats and stuff, but I am not so eccentric as to drink dashi from a martini glass – it was the best thing I had to display it in, okay?)

The classic method is to let a post card-sized piece of konbu sit, covered in a pan of water overnight. In fact, on the sacred mountain of Koya-san, the monks there would simply remove the konbu from the water and use this as their stock. 

If that’s a little too Zen for your, the more conventional way is to bring it slowly to the boil over half an hour or so. Just before the water boils, remove the konbu (it should be soft enough that your fingernail leaves a mark when you press it), chuck in a handful of katsuobushi flakes (sorry not to be specific about quantities – use the Force to decide) and, if necessary a cup of water to calm the imminent boil. Leave the flakes to infuse for a few minutes, then strain through a fine sieve/chinois. You can reuse the konbu and katsuobushi to make a slightly less refined, but perfectly tasty second dashi – niban dashi – by simmering them in fresh water for an hour or two. The Japanese use this for soups.

During my time in Japan I was shown this method by several chefs, including one who subsequently went on to get himself a Michelin star, so we can safely assume this is a reliable and trusted method.

But I was also lucky enough to eat at the fabled kaiseki restaurant, Kikunoi, in Kyoto (there is also a branch in Tokyo, but the Kyoto one is the original). It was an astonishing experience. A landmark in my life as an eater.

(October Hassan – salted ayu fish entrails with trout roe, grilled chestnut, hamo roe mousse, ginkgo sweet potato, gingko nuts and green tea noodles which look exactly like pine needles)

(this is a walnut tofu sakizuke course, made with toasted ground walnuts, ground white sesame seeds and dashi thickened with kuzu, with Delaware grapes and wasabi jelly, topped with shiso buds. Stunning flavour of toasted nuts with fresh, creamy tofu, and zingy wasabi and dashi).

(Before: Ayu fish, blurry 'cos they is jumpin').

(After: that'll learn 'em).

(Duck, roasted, then steamed, then steeped in soy stock. Surprisingly chewy, but flavourful)

I was even luckier the next day to be shown around by, and interview, Kikunoi’s head chef and third generation owner Yoshihiro Murata, a friendly relaxed guy, someone who knows his place in history is assured (not least by his stunning book, Kaiseki, with forewords by Ferran Adrià and Nobu Matsuhisa).

(Murata showing me round his kitchen)

Murata-san has worked with local university researchers to find out the optimum method for making dashi by extracting the maximum umami flavour from the ingredients.

Firstly, Murata said, you need soft water, like the water they have from the mountains that surround Kyoto (the city is famous for its water which is why its sake, tofu and fu are so renowned throughout Japan). If your water is too hard, it won’t extract the best flavour from the dashi ingredients. (Of course, I could explain to you the complicated chemical theory behind this… possibly… if I had done better than grade 4 CSE in chemistry. Let’s just say it’s to do with PH values, and draw a discrete veil over it, shall we?).

Anyway, when Murata does cooking demonstrations abroad, he takes his own water with him (as do a few of the top Japanese chefs).

At home, I use filtered water, and pretend that this is just as good. I have no idea if this is true. If you are even more of a food ponce than me, you might a) really reconsider the direction your life is going, I know I have, many times, and b) go and check out the labels on various bottled mineral waters. Volvic might well be good, I suspect.

Secondly, Murata’s researchers discovered that glutamic acid – the chief source of the umami flavour in dashi – can’t be extracted from the konbu and katsuobushi at temperatures over 80 degrees C, and in fact, 60 degrees C is the optimum temperature. He says you should keep the konbu in the water for one hour at this temperature, remove it, raise the temperature to 80 degrees, remove from the heat, and add the katsuobushi flakes. Leave them to infuse for just a minute, then drain without pressuing.

Personally, I don’t have the patience for this, and I can never resist pressing the last drops of liquid out of any stock ingredients even though I know it's wrong, but, as a result, my dashi can sometimes have a bitter aftertaste which makes my nose wrinkle and has me cursing my impatience. But then I turn the dashi into miso soup, and forget all about it.

That is my loss, of course, as a well made dashi is an utterly sublime concoction – tangy, fresh, exhilerating and tasting only mildly and deliciously of the sea.

Of course, there are countless other types of dashi, which use various other dried fish (sardines, mackerel etc), mushrooms, animal bones, vegetables and so on, but it would take a lifetime’s research to document them, and I have to sort out my accounts and water the garden and stuff, so that’s not going to happen here today.

You can use dashi as it is, as a soup. Thicken it. Turn it into a jelly. Add it to batter. Use it to make various sauces (ponzu made with fresh dashi is a revelation compared to the – already fab – bottled stuff), or of course turn it into miso soup.

About which, more in another post.