The best rye breads are made with a mix of wild-yeast starter and commercial yeast. This is what makes them so flavorful.
Rye sponge starter
1 cup barm
1 cup white rye flour
1/2 cup water
2 medium onions, diced
2 tablespoons vegetable oil
3 1/2 unbleached high-gluten or bread flour
1 cup white rye flour
2 tablespoons brown sugar
2 1/4 teaspoons salt
2 teaspoons instant yeast
2 teaspoons caraway seeds (optional)
2 tablespoons shortening or vegetable oil
1 cup buttermilk or milk, lukewarm
1/4 to 1/2 water, or as needed, at room temperature
Semolina flour or cornmeal for dusting
1 egg white, whisked until frothy, for egg wash (optional)
- Make the starter a day ahead. Mix together the barm, rye flour, and water in a small bowl, cover with plastic wrap and set it aside. Very lightly sauté the onions in the oil over medium heat just until they sweat. Transfer them out of the pan into a bowl and let them cool until they are warm, not hot. Stir them into the starter, re-cover with plastic wrap, and ferment at room temperature until it bubbles and foams, 2 to 4 hours. Refrigerate overnight.
- The next day, remove the starter from the refrigerator 1 hour before making the dough to take off the chill.
- To make the dough, stir together the flours, brown sugar, salt, yeast, and caraway seeds in a mixing bowl. Add the starter, shortening, and buttermilk. Stir until the mixture forms a ball, adding in only as much water as it takes to bring everything together into a soft, not sticky mass. Let this sit for 5 minutes so the gluten can begin to develop.
- Sprinkle the counter with flour, transfer the dough to the counter, and begin kneading the dough. Add in flour as needed to make a firm, slightly tacky dough. Try to complete the kneading in 6 minutes (4 to 5 minutes by machine) to prevent the dough from getting gummy. Lightly oil a large bowl and transfer the dough to the bowl, rolling it around to coat it with oil. Cover the bowl with plastic wrap.
- Ferment at room temperature for 1 ½ to 2 hours, or until the dough doubles in size.
- Remove the dough from the bowl and divide into 2 or 3 equal pieces. Shape them into sandwich loaves or batards for free-standing loaves. If you are baking them in loaf pans, lightly oil the pans. If you are baking them free-standing, line 1 or 2 sheet pans with baking parchment and dust with semolina flour or cornmeal. Transfer the shaped dough to the pans and mist the tops with spray oil.
- Proof at room temperature for approximately 90 minutes, or until they have grown 1 ½ times in size. The dough in the loaf should dome about 1 inch above the lip of the pans.
- Preheat the oven to 350°F for loaf-pan breads, 400°F for freestanding loaves with the oven rack in the middle shelf. Brush freestanding loaves with the egg wash. You can score them if you want. The egg wash is optional for loaf-pan breads. Place the loaf pans on a sheet pan before putting them into the oven (this protects the bottoms).
- Bake the loaves for 20 minutes, rotate the pans 180° for even baking, and continue to bake for 15 to 40 minutes, depending on the size and shape. The loaves should be golden brown all over and make a hollow sound when thumped on the bottom.
- Remove the loaves from the pan and transfer to a rack to cool for at least 1 hour before slicing or serving.
Source: The Bread Baker’s Apprentice by Peter Reinhart