Dissolve yeast in 1/2 cup warm water. Let it rest for 15 minutes. Scald the milk. Combine 1 cup sugar and 1 1/2 cups flour, and pour in hot milk, stirring until the mixture acquires the texture of sour cream. If it is too thick add an extra 1/2 cup milk. Allow mixture to cool slightly and add yeast. Beat egg yolks with remaining suagr until light. Add melted butter to yeast mixture, and then egg yolks with sugar. Gradually beat in the remaining flour. The dough will be soft, elastic, and should not stick to hands. Add candied fruit, raisins, almonds, rum, vanilla, lemon peel and salt, and knead very well, about 30 minutes. Allow dough to rise for at least 3 hours in a warm place, free from drafts, covered by a kitchen towel. After the dough has risen, place in greased and floured kulich tins or coffee cans. (Greased tins may be lined with greased brown paper.) Be sure not to fill the tin or can more than 1/3 full. Allow the kulich to rise another 30-45 minutes. Bake for about 1-1 1/2 hours at 250 to 300 degrees until puffed and golden.