As handy as a blender is, there are things your blender can’t handle. Bread doughs, for example, are too thick and sticky for the blender. Fibrous meat like beef and chicken can cause the blender to get stuck and the motor to overheat. Mashed potatoes are another no-no. The starches in the potatoes act like glue and overwork the motor. Even a high performance blender can meet its match with some of these foods.