Extreme Cuisine: We in the west have such a sweet tooth that we don't appreciate sour food. But it's about time we caught onto its attractions, writes Haydn Shaughnessy
Before God made man he made vinegar, according to the German chemist and Munich patent lawyer, Günter Wächtershäuser.
Acetic acid, vinegar by its scientific name, was there at the origins of life, he says, helping to release energy from sea minerals. It also forms an important part of the Krebs Cycle, the process that produces energy within human cells. This may explain why so many traditional cuisines make ample use of it, notably the noblest of Japanese sushi makers.
I am surprised to discover sushi, an increasingly favoured dish in the west, should be sour. Those little nori rolls of rice and fish ought to tingle with the vibrant affections of vinegar sprinkled on the raw fish, soaked into the wine.
Sushi means vinegar or sour rice. The Japanese make copious use of soured rice wine in their sushi cuisine. As the key ingredient in the rice is vinegar, the dominant taste should be one that makes the average diner wince, slightly.
By the time it reaches western restaurants and market stalls, of course, sushi sour has been transformed into western sweet.
Sushi has sourness in common with vindaloo, the Indian classic and a term that means sour wine garlic, according to Indian food writer Madhur Jaffrey. And, of course, both echo kvass, the sour ferment that ends up in Russian soups. Very few people in the west though munch on a sushi and screw up their eyes.
In a self-defeating act of culinary destruction, we tend to make our sushi sweet, as we do with vindaloo. By an act of folly, the western sushi maker replaces vinegar with sherry or simply serves rice which, as a carbohydrate, is naturally sweet, with a little fish, soy, ginger and wasabi (that green mustard that burns the inside of your nose), all sweeties of a kind.
Yet the wince-rich sours that we routinely avoid actually have a role in the creation of energy. Is that not enough to love them?
Wächtershäuser is the theorist of a "metabolic theory of evolution". Life on earth, he says, began when acetic acids came into contact with minerals such as iron and created the first acts of metabolism, by which he means the creation of energy in a form that foreshadowed proteins.
It's easy to see how vinegar, or acetic acid, played the first blinder. This is the only product that would naturally be hanging around once properly formed. Vinegar is virtually indestructible and it was there to perform life's miracle kick-start.
Vinegar can be manufactured, according to the Vinegar Institute, the international vinegar trade association, from any product that ferments into alcohol. So it can come from melons as easily as from grapes, from raspberries, potatoes, coconut or apples (a very good source), as well as rice wine.
The miracle of vinegar is that it is self-preserving. It cannot rot because it is the perfectly rotten food, forever alive in its own chemically astringent equivalent to aspic and formaldehyde.
There should be dramatic and poetic metaphors for its death-defying power but no classicist anointed it great, apart from Hippocrates who used it for medicine, no romantic extolled its virtues, it never became mangled in Joycean syntax, nobody quite got round to beatifying its presence close to the human soul. Vinegar, we owe you one.
The health and whole food community lays a special claim to its prowess. Vinegar purges, it purifies and it provides amino acids, if you source the right kind. But at the same time we are in danger of underestimating its importance.
It could be the most important chap on the digestive block.
Vinegar has been used over the full course of human history to purify foods before they are eaten. The use of vinegar in sushi is essential to a dish that contains raw fish. We are foolish enough to chance eating raw without the protection of such a powerful acid. The same can be said of any dish where it takes the lead role.
The French, for example, eat salads once they have been doused in vinaigrette, whereas we fool around with south sea island dressing and similar sweet travesties naively believing that a dressing is a matter of decoration rather than of survival.
The great sushi chef Naochimi Yusada, like many a noble sculptor of rice and fish, likes to meet his customers before he prepares, checking first if they can take a real sushi or need the westernised version. Apparently he also takes a mental note of the size of their mouths because the true art of eating sour is to eat whole rather than nibble.
The question asked by the few is what type of vinegar makes the perfect sushi. True vinegars are non-pasteurised so we can eliminate most western spirit vinegars from this particular race.
Traditionalists might argue for black vinegar, a comparative rarity even in Japan. I tried sourcing one for this article and failed. Traditionalists also warn against white rice vinegar because it is made from the dregs of sake rather than being fermented in its own right.
Brown rice vinegar has a pleasingly petillante effect on the tongue; it is a petit, dainty vinegar whereas cider vinegar is fulsome. Wine vinegars seem to me too variable and uncared for whereas everyday balsamic is a gimmick.
My tip on the vinegar trip is, above all, avoid leaving it on the shelf. Use it.
Take any excuse. Make sushi, make vinadaloo, leave behind false dressings and go back to vinaigrette, soak your salads in it, add a dash to the children's bolognese sauce. Dump the rogue balsamic. Become a sushi snob.
Ask when buying sushi: Is it really sour? If the restaurant is bold enough to say yes, ask did they use white vinegar or brown? If they say brown, ask why on earth didn't they use black?
Ask did they ever hear of Kurosu vinegar, allegedly the best out there. And if they say yes, ask if you can have some to take home. Roll it in bubble-wrap and send it to me.