Combine the dry ingredients.
Stir in the molasses and sour milk.
Fill a greased or oiled 2 qt covered brown bread or pudding mold 2/3 full, then cover closely.
Set the mold on a rack in a large kettle.
Pour in boiling water to half the depth of the mold.
Cover tightly and steam 31/2 hrs., on top of the range, keeping water boiling throughout entire cooking period, and replenishing it with boiling water if needed.
When done, remove from water, take off the lid, run a spatula between the bread and mold to loosen it, then invert on a cake cooler.
1 c seeded raisins may be added to dry ingredients.