First, make the sourdough starter. Crumble the yeast into a large bowl. Whisk in 1 quart of warm water and 2 tablespoons of sugar until dissolved. The water should be just slightly warmer than body temperature. Gradually whisk in 4 cups of flour, continuing to mix until all lumps are gone. Cover with a dish towel, and let sit for 24 hours at room temperature.
After 24 hours, stir well, cover, and let stand another 24 hours. It will be a thin, light-colored sourdough which is then ready to use.
In a large bowl, stir together the rye flour, remaining 4 cups of all-purpose flour, salt and sugar. Mix in the sourdough starter using a wooden spoon, then stir in 2 cups of warm water. I transfer the dough to a heavy-duty stand mixer to mix the first couple of minutes, then it can't handle the heavy dough and I start using my hands by turning the dough out onto a floured surface. A clean countertop works best. Knead the dough, adding a few tablespoons of water at a time if it is too stiff. Fold the dough over, pull it apart, whatever you can do to get it kneaded up good. Total kneading time should be 15 to 20 minutes to get a smooth dough. Place the dough in a large bowl, cover, and let rise until doubled, 1 to 2 hours.
When the dough has risen, scrape it out of the bowl and back onto a floured surface. Knead for about 5 minutes. This is important to activate the gluten. Shape into 1 or 2 long loaves. Place on baking sheets, and let rise for about 1 hour, or until your finger leaves an impression when you poke the bread gently.
Preheat the oven to 425 degrees F (220 degrees C). Bake the bread for about 45 minutes for 2 loaves, 1 1/2 hours if you made one big loaf. Don't worry if the crust is dark. The bread will be delicious and so will the crust. Cool completely before cutting. I always freeze half.
Notes
If you want to make extra starter for the next time, simply add 2 cups of all-purpose flour and 2 cups water to the sourdough starter on the second day, and whisk smooth. Then let stand at room temperature for 24 hours before next use. Use half, and save the other half for the next time. Let stand for 24 hours, stirring once before using. If freezing, use within 2 weeks.
Humidity and heat play a big role in making this bread. It may not work well if it is to humid and hot outside. In this case I recommend that you make the bread starting at 5am.
