The mixture will resemble heavy porridge as the rye flour absorbs the apple cider.
Sprinkle ½ cup coarse rye flour over the mixture but do not stir at this point.
Cover your bowl with a dish towel, and then wrap the covered bowl with a beach towel or blanket.
Put wrapped bowl in a warm spot (next to a heat register is good) and allow the mixture to ferment for up to 24 hours (less time if you think it will be too sour).
Dissolve 1 tablespoon yeast in ½ cup warm (105-115°F;).
If the dough seems too wet, add more rye flour (wet dough will result in a soggy baked brick).
This type of bread is tricky to make, as the dough is always very sticky from the rye; it takes some trial and error to get a feel for the dough.
If the dough is too wet, it becomes slack after a while; the correct consistency of dough remains rather firm.
Spray a formica countertop or a marble pastry board with vegetable cooking spray.
Use a small plastic pan scraper or something like that to scrape your dough out of the bowl and onto your work surface.
Using a bench knife/dough scraper, divide the dough into two equal chunks.
Wet your hands with water and keep a bowl of water handy for additional dipping.
Form the dough into two loaves on the oiled surface, using just your wet hands; do not add flour at this point.
Place the loaves into oiled bread pans (8½" x 4½").
Cover with a dish towel and let rise in a warm place.
Believe it or not, this very heavy dough will rise.
Optional (not a traditional method): brush on glaze made with 1 egg that's been mixed with 1 tablespoon of apple cider; sprinkle with rye flakes (obtainable from a food co-op).
Bake for 15 minutes at 400°F; then turn heat down to 350°F; and continue to bake for an additional hour. Don't underbake.
Remove loaves from pans and allow to cool on a rack.