You might think that a chef who was born and raised in Vermont, as I was, has as much business writing about tempura as a chef from Tokyo has writing about cheeseburgers. But any chef is bound to love the Japanese approach to cooking, an approach that puts a premium on using the freshest, best-quality ingredients and letting their natural flavors take center stage. Among Japanese cooking techniques, tempura is one of my favorites.
Tempura (the word refers to both the cooking method and the finished dish) is a wonderful frying technique that adds flavor and texture to food without competing with its natural flavor. Raw vegetables or seafood are dunked in a simple batter and then briefly fried in a mild-flavored oil, just long enough for the batter to crisp and the food to cook through. As the batter cooks, it forms a translucent coating that protects the tempura and prevents it from absorbing too much oil. Unlike some versions of batter-fried food, tempura tastes clean, fresh, and delicate.
As a technique, tempura is straightforward, and it also adapts well to American ingredients. If certain aspects of the technique don’t feel intuitive at first, particularly the slam-dunk method of battering and frying, don’t be discouraged. You’ll soon become proficient, and eventually tempura will become as valuable to your cooking repertoire as roasting or braising.
Search out seasonal vegetables and top-quality seafood
I make tempura all year long, but the vegetables I choose to fry change with the seasons. Finding exceptional ingredients is my priority, and that usually means sticking with seasonal food.
Vegetables with assertive flavors and a low water content work best for tempura. In summer, I turn to bell peppers, eggplant, green beans, and summer squashes like zucchini (with blossoms, if possible). I also dip fresh basil leaves in tempura batter (one side only) for a pretty garnish to a platter of summer vegetables. Cooler-weather vegetable candidates include carrots, sweet potatoes, and celery root. Sweet onions and fresh shiitake mushrooms are also wonderful for tempura.
In the seafood department, try shrimp and calamari tempura-style. I prefer white or pink shrimp from the Gulf or from Central or South America. They aren’t cheap, but their firmness and their clean, iodine-free taste make them worth the expense.
Cut the vegetables to sizes and shapes that let them cook at the same rate as the batter. Large vegetables should be cut into slices, thin strips, or chunks (see the chart for cutting techniques for specific ingredients); smaller, quick-cooking items such as green beans and shiitake mushrooms can be left whole. It isn’t necessary to dredge the ingredients in flour because my tempura batter clings well enough without it. But do make sure the vegetables and seafood are dry, and season the seafood with salt and pepper just before dipping it in the batter.
At the restaurant, I have a professional deep-fryer that regulates the oil temperature. But at home it’s easy enough to use large, deep cooking vessel and an accurate frying thermometer to monitor the oil. The pot should be made of heavy-gauge metal—cast iron or enameled iron are ideal because they retain heat so well. Use a pot at least eight inches deep so you can fill it with three to four inches of oil and still have a couple of inches on top to allow for splatters and bubbling. You’ll also need a mesh skimmer, called a spider, to lift the tempura out of the oil.
Use a mild vegetable oil with a high smoke point, such as canola or safflower oil. I like canola because it’s virtually tasteless. Be sure the pot is completely dry before adding the oil; water causes hot oil to splatter. If you plan to reuse the oil after frying tempura, let the oil cool completely and then strain it and store in a cool, dark place. Used oil turns rancid more quickly than fresh oil, so check it before using it again.
Heat the oil to between 350° and 360°F and monitor it periodically to maintain a constant temperature. If the temperature drops too much, the batter will absorb too much oil and you’ll get a ghastly result: greasy tempura. If the oil is too hot, the batter will brown before the food is cooked through.
A cornstarch and club soda batter buys time
Traditional tempura batter consists of just three ingredients: egg yolks, ice water, and flour. The yolks provide richness and flavor, and the flour gives structure. But the batter is tricky to use—it must be extremely undermixed to prevent gluten development, which would make the tempura tough, and it must be used within twenty minutes.
Since I’m busy enough in the restaurant without having to deal with fickle batters, I’ve come up with a version that’s less temperamental and just as superb as, if not better than, the traditional version. My batter, which uses cornstarch, club soda, and flour, contradicts the conventional wisdom of tempura, which is to always undermix the batter. In fact, this batter, which I call my “workhorse” batter, performs best when it’s smooth and lump-free; it’s virtually impossible to overmix it.
The cornstarch, which has no protein and therefore no ability to form gluten, keeps the tempura from getting tough. The carbonation in the club soda creates an airy batter, which produces light tempura. It’s true that some of the bubbles are lost during stirring, but if you set the batter over an ice bath to keep it cold, most of the aeration is preserved. Without egg yolks, the batter lacks a certain richness, so I compensate by whisking in minced fresh herbs or spices.
Although my flour, cornstarch, and club soda batter holds up well over time, it should still be prepared at the last minute since it performs best when freshly made. Sometimes the batter needs a bit of tweaking. Flours can vary in how much liquid they absorb, and humidity can play a role, too, so you may need to add a drop more club soda or a bit more flour to get the right consistency. The batter should be whisked until it’s very smooth and just thick enough to coat the back of a spoon like a custard sauce.
I think that tempura is most interesting visually and texturally when it has a translucent, almost lacy crust. If you decide that you prefer a thicker coating, you can add more flour to the batter.