1. Combine 2 cups bread flour, yeast, and 3 cups warm (90°F) water in bowl. Cover, and set in warm place 1 hour. (Mixture should look bubbly.)
2. Stir oil, caraway seeds, and salt into yeast mixture. Add rye flour and remaining bread flour 1 cup at a time until dough forms ball. Turn out dough onto floured work surface, sprinkle with flour, and knead 15 minutes, or until dough no longer sticks to hands. (Add more flour as needed.) Alternately, knead bread in food processor with dough blade 3 to 5 minutes, or in stand-up mixer with dough hook 7 to 10 minutes.
3. Transfer to lightly oiled bowl. Cover with damp towel, and let rise 1 hour in warm place, or until dough doubles in size. Punch down dough, and let rise
1 hour more, or refrigerate overnight, if desired. (The second rising time makes for a less dense bread.)
4. Line 2 baking sheets with parchment paper, or spray with cooking spray. Turn dough onto floured work surface, and shape into 2 round loaves, stretching surface until smooth, then drawing excess dough together at bottom. Pinch seam at bottom of dough. Place on prepared baking sheets, and cover with damp towel. Let rise 30 minutes, or until doubled in size.
5. Preheat oven to 400°F. Bake loaves 45 to 50 minutes, or until well-browned on outside. Cool at least 20 minutes on wire rack before slicing.
Source : allrecipes.com