To make Boston brown bread, start by greasing two one-pound (454 g) coffee cans, or molds or cans of a similar size and shape. Combine in a large bowl one cup (237 ml) of whole wheat flour, one cup (237 ml) of rye flour, one cup (237 ml)of cornmeal — usually yellow — 1 1/2 teaspoon (7.4 ml) baking soda, and one teaspoon (4.9 ml) salt. If desired, one cup (237 ml) of raisins can be added at this stage, taking care to separate any raisins that are stuck together.

Next, in a smaller bowl, combine two cups (473 ml) of buttermilk and 3/4 cup (177 ml) molasses. Stir this mixture into the dry ingredients, stopping as soon as all ingredients are moist. Fill the greased cans with the dough, and cover them with aluminum foil. To seal the cans, two layers of aluminum foil can be used, which can then be fastened around the can with string or rubber bands.

Fill a pot with water, and put some type of rack in the pans, for the cans to rest on. Put the pot, with the rack and cans in it, over a burner on low, and add boiling water until the water level reaches halfway to the top of the cans. Cover the pot, bringing the water to a gentle boil. Steam the bread this way — adding more boiling water if necessary — for two and a half to three hours, stopping when an inserted toothpick comes out clean. Carefully slide the Boston brown bread out of the can. This will be much easier if the cans were well greased before adding the dough!