To make the batter, mix all the ingredients together in a bowl.
To use the batter, heat vegetable oil to 350°F in a deep fryer or heavy-bottomed pot. Dip vegetables, seafood, or anything else you desire into the batter, and deep fry until pale golden brown. Drain the tempura on a wire rack.
Video
Recipe Tips
Keep everything cold. The batter should be mixed and used immediately. As batter warms, carbonation dissipates and gluten develops faster, both of which produce a heavier crust. If you are frying multiple batches, set the mixing bowl over a larger bowl filled with ice to keep the batter cold throughout the process.
Fry in small batches. Adding too many pieces at once drops the oil temperature. When the oil cools below about 325 degrees F, the batter absorbs oil instead of crisping, and the finished texture turns greasy. Allow the oil to return to 350 degrees F between each batch before adding more food.
Pat food dry before battering. Moisture on the surface of shrimp, fish, or vegetables repels batter and prevents it from adhering. A quick pat with a paper towel gives the coating something to grip.
A wire rack is not optional. Paper towels soften tempura within a couple of minutes. A wire rack lets air circulate underneath the fried pieces and keeps the crust intact while you finish frying the remaining batches.