Before pureeing beets, they need to be cooked. You can buy pre-cooked beets, or steam them yourself in a steamer pot. To do this, wash the beets, peel the skin and cut them into bite-sized pieces. Place the beets in a steamer pot (with water at the base) and steam them on the stovetop until tender. Next, place the steamed beets in a food processor or blender and blend until they form a jelly-like texture.