The first cooking oil used in Japan was probably sesame oil,goma abura, introduced by the Chinese during the eighth century (see japanese cooking implements ). Although sesame oil is still popular, the Japanese today use mainly refined, flavorless vegetables oils for deep-frying. As in the United States, sarada abura, “salad oil,” can be canola, soybean, cottonseed, corn, safflower, or sunflower oil, or a combination of two or more of these. Because sunflower and safflower oils, when heated to frying temperature, are easily oxi dized and take on a bitter taste, these light oils are best used in preparing dressings. For deep-frying as well as sauteing and stir-frying, the more heat-stable oils—canola, soybean, corn, and sesame—are preferable.
The rules for successful deep-frying are universal:
- Maintain a constant proper temperature to produce the best results—a crisp out side and a juicy inside. Because it can easily maintain a constant temperature, a large, heavy, flat-bottomed iron pot is ideal for deep-frying.
- Do not crowd pieces of food in the oil, or they will absorb moisture from each other’s steam and become soggy. It is ideal to leave two-thirds of the surface unoccupied by frying foods.
- While frying, continually skim the oil to remove burnt batter or other bits of food. This prevents the frying foods from taking on a bitter flavor and burnt color.
- After foods are fried, drain them on a steel rack or paper towel. Never pile or even overlap them, or the steam they emit will make them soggy.
- Be sure your oil is fresh. Keep it in a tightly capped container in a dark, cool, and dry place. Once the container is opened, use the oil as soon as possible.
Deep Frying Method
To check the temperature offrying oil, use a thermometer if the oil is deep enough. If the oil is only 1 to 2 inches deep, or ifyou have nothermometer handy, you can substitute either of one or two methods, using cooking chopsticks or batter. To check the oil temperature with cooking chopsticks, submerge their tips in the oil. When the temperature reaches 320 degrees F(low frying temperature), tiny bubbles will start emerging from the tips ofthe chopsticks. When the temperature reaches 340 degrees F (medium frying temperature), larger, brisker bubbles will rise from the chopsticks. At 360 degrees F (high frying temperature), the bubbles will be slightly larger still and very brisk.
To use the batter method, drop a very small amount oftempura or other flourwater batter into the heated oil. At 320 degrees F, the batterwill sinkto the bottom, and then float to the surface after a few seconds. At 340 degrees F, the batter will sink to the bottom but rise more quickly. At 360 degrees F, the batter will not sink at all, but will break up and scatter over the surface of the oil.