Light Tempura Batter

The secret to an exceptionally light, lacy tempura crust is carbonation. Club soda or sparkling water introduces carbon dioxide into the batter, which expands rapidly during frying to create air pockets and a delicate, open texture. Adding a small amount of baking soda alongside club soda amplifies this effect: the baking soda reacts with the carbonic acid in the water to release additional gas. Using a cream whipper charged with CO2, as done here, takes it a step further, producing an even finer, airier batter. Keep all ingredients cold, work quickly, and do not overmix. In tempura batter, lumps are not a problem and actually help produce a lighter result.