batter for tempura is generally made from cold water and a light wheat flour. however, sometimes other ingredients may be added, such as eggs, baking soda or baking powder, starch, oil, or spices. traditionally, the batter is mixed a small amount at a time using chopsticks. the batter is only mixed for a few seconds and the lumps are left behind, giving the fried tempura its unique shape. great care is taken to make sure the tempura is not over-mixed, otherwise it will become chewy and dough-like.