Feed starter 4-8 hours before using. I purchased mine from Ballerina Farm. The time it takes to rise will depend on how warm your house is. You want it to double in size. Use a kitchen scale to feed the starter in a mason jar by mixing 50g starter and 50g warm water and mix using a wooden spoon to loosen it up. Then add 50g of bread flour and mix until no more patches of flour are visible. Cover with plastic wrap and let it sit at room temperature until it activates and doubles in size. I usually place a rubber band around the mason where the starter stops to gauge the growth. The starter should look very bubbly at this point. (Tip: if you want to bake 2 loaves, you’ll need to feed double the amount of starter. So 100g of each water, flour, and starter). In a bowl, mix 350g warm water no higher than (110°F) with 100g of active starter. Then add 12g salt and mix in 600g bread flour. I love using a dough whisk and scraper for this step.
It will look shaggy and dry and that’s ok. Cover with plastic wrap and rest for 30 mins in a warm place. I like to use the proof setting on my oven for this step.
Now begin the stretching process. Without removing the dough from the bowl, pull the top into the center, then the left side into the center. Then the bottom and right sides into the center. So pretty much pull in all the sides of the dough. Then cover with plastic wrap and let it rest for 30 more minutes at room temperature.
After the 30 minutes have passed, repeat the same stretching process 5 more times with 30 minutes in between. So a total of 6 stretches. Do not skip the stretching. This is very important for sourdough. With each stretch, you will notice the dough getting stronger and stronger. Building the strength of the dough will help hold its shape when it bakes.
After the last stretch, place the dough on a clean work surface and stretch it into a small rectangle (doesn’t matter how big). Now, fold it into 3rds and roll it up so the seam is on the inside. Then use your hands to shape the dough into a round ball by turning it on your work surface multiple times.
Now thoroughly dust your bread-proofing basket with about 1 Tbsp of rice flour and 1 Tbsp semolina flour. Note: dusting with bread flour will not work. The dough will stick to the bread basket. Place the dough into the bread-proofing basket and dust with a little more semolina and rice flour. Then cover and chill the fridge for 8 hours or overnight. Tip: if you do not have a proofing basket you can line a glass bowl with a kitchen towel and dust it with rice flour and semolina.
In the morning, take the bread dough out of the fridge and let it come to room temperature for about 3 hours.
Place an empty Dutch oven pot (with lid) in the oven and let it preheat to 450 degrees Fahrenheit. Carefully flip the bread dough onto a sheet of parchment paper. Use a blade to make a few slits or designs on top of the bread Scoring the bread will control where the air will expand. Then place it inside the hot Dutch oven pot and put the hot lid on top. Be careful, it will be very hot.
Bake it covered for 30 minutes, then uncovered for 15-20 minutes. Let the baked bread cool before slicing.