The tempura method of deep-frying was originally introduced to Japan by Portuguese missionaries and traders in the 16th century. The word tempura is thought to come from the Portuguese word temporas, meaning Lent: The reason given is that the Portuguese Catholics would eat fish only on Fridays, and often deep-fried it. Another word sometimes suggested as the origin is tempero, which means seasoning.
In the days when large families and houses were common in Japan, tempura was often made at home: kitchens were large, so spattered oil didn't cover everything in the room and any smoke soon dissipated. But now that nuclear families and small living quarters have become the norm, the making of tempura has drifted away from the home and into specialty restaurants, which can more easily manage the large quantity of oil required. And although tempura batter is basically just egg, flour, and cold water, it is rather difficult to make well; the proper oil and the correct oil temperature are also critical to good results.
Tempura is best when eaten soon after being fried. If too much time passes, the water in the ingredients will seep out and the batter coating will lose its crispiness. This is why tempura restaurants will often fry and serve your order a few pieces at a time, allowing you to enjoy it at its best.
Considered a special treat, popular tempura ingredients include shrimp, white-meat fish, aubergines, sweet potato, shiitake mushrooms, or a mixture of small shrimp and vegetables. These are served with a dipping sauce made from soy sauce, mirin, and dashi, and condiments such as grated daikon radish and grated ginger, which enhance the flavour and aroma.
To eat Tempura, first mix one or more of the condiments into the sauce, then dip the tempura in as you eat. Some people also just sprinkle it with salt.
Don't hesitate to try tempura just because it is deep-fried. It has a very light, delicate texture and a clean taste that brings out the natural flavour of each ingredient, making it one of the greatest delights of Japanese cuisine.