Dissolve the yeast in the lukewarm water. Add the cold water. Sift together the sifted all-purpose flour and salt. Stir into the yeast mixture and beat vigorously until smooth. Cover and place in the refrigerator overnight. In the morning, stir in the molasses and melted butter. Dissolve the baking soda in the hot water and add to the mixture. Let stand at room temperature for 30 minutes. Drop the batter onto a hot grill or skillet, spacing the cakes well apart to allow room for spreading. When bubbles appear on the surfaces and are beginning to break, use a spatula to lift the edges to see whether the undersides have browned. If so, flip and cook the other side until just done. Makes about 36 4-inch pancakes.