Add yeast to lukewarm water and let stand 5 minutes. Add eggs, sugar, and salt; mix well. Mix the melted butter and warm milk together, add this and the flour alternately to the egg mixture. Mix with a spoon until quite stiff. Then knead with hands until dough is smooth and springy. Place into a fairly large bowl, cover with a towel, and let rise in a warm place for 1 1/2 hours or until doubled in bulk. Shape into 2 large braids or 1 1/2 dozen buns. (Buns are made by rolling a ball of dough out about 4-5" in length and forming into a knot.) Cover and let rise 1 1/2 hours or until doubled in bulk. Punch down; let rise again. Bake braids at 350* for approximately 20 minutes. Bake buns at 400* for 10-15 minutes. Immediately after removing from oven, brush top with slightly beaten egg whites and sprinkle with granulated sugar. Finely chopped nuts or candied fruits can also be added.