In a large bowl, proof the yeast in 1/2 cup warm water until slightly frothy. In the meantime, dissolve 1/2 cup sugar in the warm milk, then cool to lukewarm.
Next, add the milk mixture to the yeast mixture along with four cups of flour. Mix well with a wooden spoon. Cover and put in a dark, warm place until the mixture is bubbly and double in size. This should take about 2 hours.
Stir in until well blended the beaten eggs, 1/2 cup sugar, margarine or butter, salt, and lemon peel.Add the remaining flour, a cup at a time, to form a very soft dough. Knead the dough on a floured board until soft and elastic, about 10 minutes.
Place the dough in a greased bowl, turning to coat both sides. Allow it to rise in a warm place until doubled, about 2 hours. Punch the dough down and allow it to rise again for 30 minutes.Divide the dough into three parts. Shape into slightly rounded loaves, and place on greased baking sheets. Let rise until doubled, about 45 minutes to 1 hour. Beat 1 egg with 1 tablespoon water; brush onto loaves.Bake at 350 degrees F (175 degrees C) for 45 to 50 minutes, or until done.
Once they are done, brush the tops with melted butter for a soft crust.
