This huge variety of small, elegant Japanese foods is based on a special variety of short-grain rice that is lightly vinegared and then served with a selection of raw or cooked fish and vegetables. These are commonly rolled together in a wrap of nori seaweed and then sliced to make pieces of beautiful appearance. Sometimes the rice is dextrously shaped in the palm and served with raw fish atop it and some varieties are based on omelette. There are hundreds of variations and combinations.
Classically, sushi should be prepared before you, so the precise temperature and texture of the rice and of the accompaniments coincide to give a fleeting, precise experience typical of refined Japanese culture. Chefs’ views differ but the general objective is human body temperature or a little less but unlikely to be less than 90C.
Californian-style sushi began when chefs there substituted avocado for tuna. It commonly uses crab substitute rather than the real thing and rolls the nori sheets inside the rice, making them seem inside out but the style has flourished and changed considerably.
Sushi is served with wasabi, a very hot type of Japanese horseradish and with soy sauce, but overuse swamps the sushi and thus negates the expense and experience. Sushi should not be confused with sashimi, which is very finely sliced raw fish and seafood.
Once skilfully prepared by highly trained chefs only in dedicated speciality establishments, sushi is now served in large restaurant chains, sometimes on moving belts, in dedicated shops and from supermarket shelves. These latter two will be refrigerated, which reduces the flavours and changes the texture of the rice.
Choose the best
Provided they are very fresh, shop bought sushi can be a good introduction and they are widely enjoyed as a low-fat, low-calorie snack or light meal. For best results, bring them to room temperature before eating.
Don’t. Sushi should be eaten as soon after purchase as possible. Raw ingredients will quickly oxidise or deteriorate and develop off flavours and smells.
You need special rolling mats, a very sharp knife and a deft hand at slicing finely plus highly developed shopping skills if you are basing homemade sushi on raw fish; the best sushi quality of, say, tuna, is searingly expensive and it’s hard to judge its freshness as an amateur. If you have the tools and the inclination, making sushi is great fun as a joint or family enterprise.
Pioneering BBC-TV Chef Glynn Christian is author of REAL FLAVOURS - the Handbook of Gourmet and Deli Ingredients, voted 'World's Best Food Guide'.