My take on Eric's Favorite Rye from TheFreshLoaf.com. If you don't have a rye sourdough starter, just use your white starter. Preparation time includes rise times for the sponge and the overnight rise in the fridge.
Mix the sponge ingredients, cover and set at room temp until doubled in volume.
Mix the dough ingredients into the sponge and, rest for 20 minutes. Dough will be very sticky. Rye doughs resemble wet cement. The rest will help a good deal with the stickiness.
Knead by machine (recommended) or by hand for 8 minutes. Tip dough onto counter and stretch and fold the dough letter-style.
Place dough in a straight-sided oiled container. Cover and ferment till double (1-1.5 hour or so at warm (80 F) temperature). Be sure it doubles in volume.
Divide and shape into 2 loaves and place in bowls or bannetons or in a couche for support. Cover with oiled plastic and refrigerate immediately.
Overnight, the loaves should rise about 50% in volume. Place on counter while preheating the oven with a water pan to 400°F.
Glaze with an egg and 1 tsp water, slash the loaves, and bake at 375°F with steam for 12 minutes then remove steam pan and rotate loaves. For glossier finish, add more glaze. Bake for 30 more minutes until 200F internally. Cool on a rack.