90 grams sourdough starter, 100-percent hydration
420 grams water
590 grams flour (King Arthur All Purpose Flour for expert, King Arthur Bread Flour for a beginner)
10 grams whole wheat flour (Bob’s Red Mill Organic Whole Wheat Flour)
13 grams sea salt
2 teaspoons instant dry yeast at 60F, 1.5tsp at 68F, and 1 tsp at 75+
Olive oil to grease bowl
Cornmeal or semolina to dust cutting board
Pour starter and yeast into bowl and add water, mixing until the starter breaks up a bit.
Add flours and mix for a couple of minutes. The dough will be heavy and shaggy. Make a slight pool in the top of the dough and add the salt, with 1 teaspoon of water. Let it rest for 10-15 minutes covered
Knead by stretching and folding dough, and incorporating the salt. After kneading for 3 minutes, scrape mass into a clean bowl or plastic bin. Cover and let rest for 20 min.
Stretch and fold top and bottom then left and right. Cover, let dough rest 20 minutes.
Remove from bin, fold again, and put back in covered bin for 20 minutes.
Remove from bin, fold again for the third and final time. Clean bin, oil lightly and refrigerate for 12 to 24 hours.
Put baking stone in middle of oven. Place a thick rimmed cookie sheet or cast iron pan on oven floor or lower shelf. Preheat oven to 470F (245 C).
Put a little olive oil in your palm and oil a 20-by-20 inch (1/2-by-1/2 meter) section of the counter.
Then remove dough from container. Cut dough in half. Put half back in container and into refrigerator.
Cut dough into two rectangular pieces (about 250 grams each) and gently stretch into rectangles 5-by-7 inches (13-by-18 cm) with the long edge facing you. Gently form into a log.
Cover with light towel and let rest for 15-20 minutes.
Shape dough into a log by folding top into middle, stretching the outside “skin”. Do it again. Rotate the dough 180 and fold in with left hand while sealing the seam with the right palm. Do that again. You should have a dough about 2” thick and 8-10” long. Gently roll and stretch into a 14-inch loaf (36 cm) or just under the size of your baking stone. Watch this video: www.chewswise.com/chews/2011/03/14/how-to-shape-and-score-a-baguette
Place each loaf on couche with loose pleats between the baguettes
Cover with light kitchen towel and let rise for 45 minutes to 1 hour.
Put 2/3 cup water in measuring cup.
Transfer to transfer board
Make four cuts on the top of the loaf with a razor blade, 1/4-inch deep
Transfer baguettes onto hot baking stone. Shut oven door. Open door, and carefully pour 2/3 cup water onto cookie sheet or cast iron pan. Shut door. Do not open the oven again while baking.
Check baguettes after 18 to 20 minutes. They should be dark brown and crusty. If pale, continue baking for 1 to 2 minutes. Let cool for 20 minutes on rack before eating. They are best eaten within 6 hours.