Authentic Boston Brown Bread

Mix the rye flour, cornmeal, whole-wheat flour, baking soda, and salt in a large bowl. Stir the dry ingredients with a fork to lighten and mix. Add the molasses and milk and blend well. The batter should be the consistency of pancake batter. Butter a 1-quart pudding mold or a l-pound coffee can, and pour in the batter, filling the mold no more than two-thirds full. Cover tightly (if using a coffee can snugly fit aluminum foil on top) and place in a deep kettle. Add boiling water halfway up the mold. Cover the kettle and steam for about 1 1/2 hours, or until a broom straw comes out clean when inserted in the middle of the bread. Remove and cool on a rack. Serve warm.