Basic Sourdough Boule - 70% Hydration

Instructions

Make sure you have an active poolish sourdough starter that has been recently refreshed. I prefer to discard most of my sourdough starter the night before and refresh with cold water and flour at a 1:1 ratio of flour to water, with half of my flour being bread flour, and the other half being whole wheat. I will then set the refreshed starter out at room temperature overnight, or for around 8-12 hours. For this particular recipe, you want to have at least 600g of sourdough starter, 500g for the above recipe, with 100g leftover which you will then feed and store for later use.
Whatever method or schedule you use to keep your sourdough starter strong and full of life, test it's strength right before baking by dropping a tablespoon's worth into room temperature water. If it floats, then you know your starter is active enough to levin a loaf of bread. If the starter sinks to the bottom of the container, it is not yet active enough for baking and will likely need a few more hours of fermentation at room temperature.
Combine warm water and poolish starter together, mixing with your hand or a wooden spoon to evenly distribute the starter throughout the water.
Place bread flour and whole wheat flour on top of water/starter mixture, mixing with your hand to thoroughly combine. Cover with plastic wrap and allow to autolyse (rest at room temperature) for 30 minutes.
After 30 minute autolyse, measure out 15 grams of kosher salt and mix into dough.
Turn dough out onto a clean work surface. DO NOT use flour or non-stick spray. Embrace the stickiness of the dough, slapping, folding and stretching the dough on your work surface to form a strong gluten network. For further explanation of this technique, please view the video above.
Once the dough has a strong gluten network, very lightly dust your work surface with flour, place the dough on top of the flour and perform a standard stretch and fold, resulting in a rounded, cohesive piece of dough (see video).
Repeat stretch and fold every 10 minutes for a total of 3 times.
Bulk ferment at room temperature for 2-4 hours, or until the dough's volume has increased by 1.5 times its original size.
After bulk fermentation, gently turn dough out onto your work surface, being careful not to compress or overly "de-gas." Over working or "flattening" the dough at this point will yield an undesirably dense crumb.
Form dough into a round boule, using tension pulls to to create a tight gluten structure on the surface of the dough (see video). Allow to bench rest, covered with plastic wrap, for 10 minutes, after which another round of tension pulls is performed to create a well structured loaf that will hold its shape during proofing and have superior oven spring.
Place shaped dough seam side up in a proofing basket and that has been generously dusted with flour. If a proofing basket (banneton) is unavailable, an appropriate sized bowl, lined with a lint free towel that has been generously dusted with flour will work nicely.
Cover proofing basket with plastic wrap (insuring the surface of your dough doesn't dry out) and allow to proof for 2-3 hours, or until the dough has increased by 1.5 times its pre-proof volume.
While dough is proofing, place a large (I use a 7 qt in the video) dutch oven, with lid, inside your oven and pre-heat to 500°F/260°C, at least 45 minutes prior to baking.
After dough has proofed, gently flip the dough into the pre-heated cast iron dutch oven so that the seam side, (which was up during the proofing stage), is now down, in direct contact with the bottom of the dutch oven.
Score the top of the loaf with a sharp baker's razor or pairing knife, using whatever design you prefer. A # sign is always a simple option that works well.
Cover dutch oven with lid and bake covered in 500°F/260°C oven for 20 minutes.
After 20 minutes, remove lid from dutch oven, turn oven down to 425-450°F/215-230°C, and bake for another 30 minutes, or until the loaf is dark brown. Everyone's oven is different, so please pay attention during the final stages of baking. If it looks like your loaf is browning too quickly, reduce oven temp slightly and continue to bake. Remember, you want a dark brown crust with portions flirting with burnt.
After 30 minutes of baking, check bread for doneness by removing loaf from dutch oven and thumping on the bottom with your thumb. The loaf should sound hollow when thumped and feel light for it's size. Place finished loaf onto a wired cooling rack and allow to cool to room temperature before slicing (this will take at least 1.5-2 hours).
Slice and enjoy.

Notes

This is a basic recipe for a "country style" sourdough loaf. As your confidence with baking sourdough bread grows, here are some fun things you can try:

Raise hydration rate to 75%-80%. This will make your dough harder to work with but yield a more open crumb if that's what you're after. If going this route, I would recommend doing a stretch and fold 5-6 times at 20 minute intervals. Perform the stretch and fold in a large bowl, using a wet hand to pull one edge of the dough over the opposite edge, continuing around the bowl until the dough has gone through a complete stretch and fold. The "slap and fold" kneading method can be omitted with higher hydration loafs.
Make the Kalamata Olive and Rosemary loaf served at Stella by adding a handful of rough chopped Kalamata olives and one sprig of fried rosemary (minus the sprig) to the dough after autolyse, at the same time the salt is added.
Add extra character by using 10% dark rye, 10-20% whole wheat flour and some fennel seeds.
Make a seeded loaf by adding a 1/4 cup of your favorite seeds (sunflower, poppy, sesame, pumpkin, etc).
Break the bulk fermentation and proofing phases into multiple days for a more complex and sour flavor and for added convenience. For example, day one, mix, autolyse and perform stretch and fold on the dough. Place in proofing container, covered with plastic wrap, and leave in your fridge until you have free time the following day. The next day, let dough come to room temp (about 1-2 hours), form, place in proofing basket. At this point you can allow to fully proof or place back in refrigerator overnight. The next day, remove dough from fridge and allow to come to room temperature for about 1-2 hours before baking. Bake as demonstrated in the above video.
If at any time in the baking process you're in a bit of a hurry, place dough (either in the bulk fermentation phase or proofing stage) in your oven (make sure it is NOT ON). Place a pan of boiling water in your oven which will raise the temperature and humidity, effectively turning your oven into a proofing chamber, speeding up bulk fermentation and proofing.
Try adding dry fruit, nuts, cheese or a mix for a special loaf of bread. One of my personal favorites is blue cheese with toasted almonds and dried cherries that have been rehydrated in water, and the water itself is then used in the bread recipe. Add extra ingredients between autloyse and kneading process, at the same time as the salt.

Those are my ideas, what are some of yours? Let's talk about them in the comment section below!