Native Americans had made corn bread and baked beans. The Pilgrims at Plymouth Colony learned these recipes in the early 1620s and likely added barley to the corn meal to invent New England brown bread. The Triangular Trade of slaves in the 18th century helped to make Boston an exporter of rum, which is produced by the distillation of fermented molasses. At that time, molasses was added to local baked bean recipes, creating Boston Baked Beans. In colonial New England, baked beans were traditionally cooked on Saturdays and left in the brick ovens overnight. On Sundays, the beans were still hot, allowing people to indulge in a hot meal and still comply with Sabbath restrictions. Brown bread and baked beans were a popular meal on Saturdays and Sundays in Massachusetts until at least the 1930s.