Generously grease a 1-quart pudding mold or 1-pound coffee can.
Combine the flour, baking soda and salt in a mixing bowl. Stir in the molasses and milk. Fold in the currants.
Fill the mold or coffee can with batter. It should come up about two-thirds of the way. Cover the top with foil and tie securely with a string to make it airtight.
Place in a deep baking pan and fill the pan with boiling water, to come halfway up the side of the mold.
Place in the preheated oven and allow to steam for 2 hours, checking the water level after 1 hour.
Add more boiling water if needed. Check by sticking a skewer into the bread; it will come out clean when done.
Remove string and foil and allow to cool for 1 hour before unmolding.
Jasper White's Cooking from New England by Jasper White