This recipe uses almost all rye flour (75%). You can work your way up to 100% rye but I would recommend starting lower, using wheat flour to lessen the density a little bit. Still, this bread is delicious, just the thing for a true rye lover. (NOTE: Don't get discouraged with the way this dough handles. Rye dough is not soft and pliable like wheat dough. Just go with it.)
Here's the recipe:
375 g dark rye flour (2-2/3 cups)
125 g bread flour (just under 1 cup)
350 g water (1-1/2 cups)
2 tsps instant yeast
2 tsps sea salt
2 tsps caraway seeds
1 Tbsp molasses
Pinch of brown sugar
1 Tbsp canola oil