Dissolve yeast in 1/2 cup warm water (105 to 115 degrees--pretty warm but not hot when you put a little on your wrist). Let stand 5 minutes or until bubbly.
Combine the rye flour, molasses, shortening or lard, and salt.
Add boiling water and stir until shortening is melted. Cool to 105-115 degrees. Stir in dissolved yeast.
Gradually add all-purpose flour (or enough to form a soft ball).
Turn dough out onto a floured surface. Cover and let rest 10 minutes.
Knead dough 10 minutes, or until smooth and elastic. Shape into a ball and place in a greased bowl; turn over to grease top. Cover and let rise in a warm place (85 degrees), free from drafts, for 2 hours, or until doubled in bulk. Note: I put plastic wrap over the dough, cover with a couple of towels, and put the whole thing into the microwave, which Iíve previously prepared by heating a cup of water for a couple of minutes. When I take out the water, the microwave is warmed inside and makes a cozy place for the bread to rise.
Punch dough down, and repeat the rising procedure for another 30 minutes.
Turn dough out onto a lightly floured surface. Divide into three equal portions, shaping each into a smooth ball. Cover and let rest 15 minutes.
Shape into round loaves, and place on a greased baking sheet. (Double the sheet if yours are thin, to prevent the bread from scorching.)
Cover and let rise again for 1 hour or until doubled in bulk. Preheat oven to 350 degrees.
Brush tops of loaves with lightly-beaten egg. Bake for 40 minutes or until loaves sound hollow when tapped. Transfer to wire racks to cool. When cooled, put in ziploc bags to store. Since you havenít added preservatives, you will need to store airtight in refrigerator or freezer.
Makes three round loaves.