2-3 cm. When eating stinky tofu, it is usually most appropriate to use a bamboo stick about 2-3 cm long. Too long bamboo sticks are easy to be wrapped with stinky tofu, which is inconvenient to eat, and too short bamboo sticks are easy to fall off, which is unsafe and inconvenient. Therefore, it is most appropriate to choose a bamboo stick with a length of 2-3 cm, which can conveniently clamp stinky tofu without falling too short.