Wash beets carefully to avoid breaking the skin and so loss of color while boiling. Boil rapidly until tender. New beets will cook in one or two hours. Old beets can hardly be cooked enough. When tender drain and cover with cold water to loosen the skins. The skins should be removed with the hands. Season with salt, pepper, and butter. If the beets be large, cut in slices. Beets left over may be covered with vinegar and kept for several days. Beets baked in a hot oven are particularly good. When cooked cut these in slices, dress with butter, pepper and salt.