Dissolve yeast in 1/2 cup warm water. Combine in bowl with boiling water, oats, molasses, shortening and salt. Cool to lukewarm and stir in 2 cups flour, eggs and yeast. Beat well and add last measurement of flour. Dough will be a little sticky. Grease top lightly, cover tightly and place in refrigerator at least 2 hours or overnight. Turn on well-floured surface and shape into 2 loaves. Let rise 2 hours or overnight. Bake at 350° 40 minutes.