Tempura-style batters were originally brought to Japan by Portuguese missionaries in the 16th century.* Since then, tempura has been perfected to a near art form by Japanese chefs. At the best tempura houses in Japan, all of your courses will be cooked by a single tempura chef who spent years in apprenticeship before ever being allowed to touch the batter or fry oil.
*The word tempura itself comes from the Portuguese, as do many other Japanese words. According to Harold McGee's On Food and Cooking, tempora means "period of time" and refers to the fasting seasons during which fried fish was consumed in place of meat. These days, the word refers to any battered and fried item cooked in the manner of tempura fish, much like Americans have their "chicken-fried steak"—steak cooked in the manner of fried chicken.
Tempura chefs are sort of like the Jedi of the cooking world: They must deftly perform with the utmost skill and precision, using extremely dangerous tools, all while maintaining a calm, serene demeanor. It is an elegant technique, from a more civilized time. The bad news is that you, I, and the vast majority of people in the world are never going to become as great as the masters who spend their entire lives training. But the good news is that we can get about 90% of the way there right off the bat.
The key characteristics of a tempura-style batter are extreme lightness of color and texture: Good tempura should be pale blond with an extraordinarily lacy, light, and crisp coating. To achieve this takes just a little more care than other types of batter. Traditional tempura batter is made by combining flour (usually a mix of wheat flour and lower-protein-rice flour—I use wheat flour and cornstarch instead) with eggs and ice-cold water. The batter is mixed until just barely combined so that plenty of pockets of dry flour remain and virtually no gluten development occurs. A tempura batter has a lifespan of only moments before the flour becomes too saturated with water and a fresh batter must be made. But there are ways we can improve on this fickleness, so long as we aren't married to tradition.
First off, using the old vodka-in-the-batter trick (which by now you may be sick of) works very well, limiting the rate of gluten formation so that the batter can sit a bit longer before it goes bad. So does replacing the ice water with club soda, a trick I learned from my old chef Ken Oringer, at Clio Restaurant in Boston. But the real key is in the process: Rather than simply dumping the dry and wet ingredients into a bowl and whisking them together, I found that by adding the wet ingredients to the dry, then immediately lifting up the bowl and shaking it with one hand while simultaneously rapidly stirring with a pair of chopsticks, I could get all of the ingredients incorporated while minimizing the amount of flour that is completely moistened by the liquid.
How to Prepare Common Tempura Ingredients
|Green beans||Trim the ends|
|Mushrooms||Clean and thinly slice, or leave thin mushrooms like shiitake or oyster whole|
|Bell peppers||Cut into 1/2-inch-wide rings or strips|
|Zucchini and summer squash||Cut into 1/2-inch rounds or sticks|
|Onions||Cut into 1/2-inch rings|
|Eggplant||Cut into 1/2-inch rounds|
|Sweet potatoes||Peel and cut into 1/4-inch slices|
|Butternut squash||Peel, seed, and cut into 1/4-inch slices|
|Okra||Trim the stem ends|
|Broccoli and cauliflower||Cut into 1-inch florets|
|Carrots||Peel and cut into 1/4-inch slices or planks|
|Shrimp||Peel, leaving the final tail section intact if desired, and remove the legs. Flatten each shrimp, and insert a wooden skewer lengthwise to keep it straight while it fries; remove the skewers after cooking.|