Dissolve yeast in 1 cup lukewarm water to which 2 tsp of granulated white sugar has been added. Whisk after 5 minutes. Sift together flour, 6 tbsp granulated sugar and salt. Add raisins. Set aside. Combine 3 cups lukewarm water, molasses and melted butter. Stir in dissolved yeast. Add dry ingredients and raisins. Knead for 10 minutes. Place in greased bowl and turn dough over 2 or 3 times to grease the top and prevent crust from forming. Cover and let rise until doubled, approximately 2 hours. Knead dough and divide into 4 or 5 pieces. Form into loaves. Place in greased pans and let rise in warm area until doubled, approximately 1 hour. Preheat oven to 325 F. Bake until loaves give hollow sound when tapped on the bottom, approximately 30 minutes. Turn out of pans, brush with melted butter while hot.