(We also have a Sourdough Starter Kit which has everything you need to start your sourdough journey)
The day before you plan on baking, feed your starter. A good rhythm can be to feed the starter in the evening before bed and use it in the morning. In order for the bread to get a good rise, the starter must be at peak activity when you use it in the recipe.
It may be helpful to leave your starter on the kitchen table and give it several feedings in the days prior to using it in a recipe so that you can observe the rise and fall of your starter and judge the timing of your baking accordingly. Use a small jar with clear sides so that you can see the mixture climb the sides and so that you will see the gas bubbles in your starter develop as it ferments.
A rubber band stretched around the sides of your jar is helpful to measure the line of your starter when you first feed it so you can better judge the amount of rise that you get. The fermentation is very temperature sensitive (the ideal temperature for sourdough fermentation is between 21-25 degrees celcius, if the environment is colder the process will take longer and if it is warmer it will take less time) so adjust your timing accordingly. A seedling heat mat with a digital thermostat controller works well for controlling the temperature of the dough or sourdough starter.
When you think the starter is ready to use, take a spoonful from the jar and taste it. You should notice a distinct change in texture from a flour/water mixture to a gassy, goopy substance. It should taste slightly sour, even effervescent, but not too vinegary. If the starter tastes like flour and water, it needs to mature more.
Heat the water to 25 degrees celcius. Measure the temperature using a kitchen thermometer or if you don't have one, test the water with your finger. It should feel warm, not hot.
Measure the water into a bowl and add the flour to it. Incorporate with a wooden spoon. Once the dough becomes too thick to stir with the spoon, wet your hands and mix the rest together with your hands until the dough forms a shaggy ball. Cover with a towel and let rest in a warm place or on your heat mat for 45 minutes to autolyse.
Uncover the bowl and add the activated sourdough starter and salt. Mix in thoroughly with wet hands. Set the dough aside in a warm place for an hour or until the dough ball has relaxed and spread out into a smooth-looking dough.
After about an hour, uncover the bowl, and with two wet hands slightly tilted downward, lift the dough from the middle and let it hang. The dough will stretch as it hangs. Let the dough stretch, then drop the middle part onto the resting hanging ends.
This step builds strength in the dough. Cover the bowl again and set it aside in your warm spot to let the dough ferment for 1 hour. Then repeat the lifting, hanging, and dropping process 2 more times, allowing 1 hour of fermenting after each session, including the final one.
After the dough has fermented for that final hour, moisten your hands and loosen the dough from the sides of the bowl, then turn it out onto a surface sparingly brushed with water
SHAPE THE DOUGH
With two wet hands slightly tilted downward, lift the dough from the middle and let it hang. The dough will stretch as it hangs.
Let the dough stretch onto the work surface, then drop the middle part onto the resting hanging ends
Repeat the lifting, hanging, and dropping process once more.
Drag the dough across the surface toward you with both hands.
Turn it 90 degrees and drag it until you have a rough ball. Set aside to ferment at room temperature, uncovered, for 1 hour.
GIVE THE LOAF ITS FINAL SHAPE
If your dough feels quite sticky, sprinkle a bit of flour on your work surface. Otherwise, a light sprinkling of water on the working surface will do.
With wet fingertips, press into the surface of one piece of dough, working vertically (down toward the work surface) to elongate the dough.
Flip the bottom half of the dough over the top half. Grab each side of the dough and stretch it gently to its limit , the dough will tell you how much it can stretch. Return it to the work surface. Fold one end to the center of the dough, then fold the other end over the folded dough. Working from the edge closest to you, roll the dough over itself . Drag the dough across the surface toward you with both hands to seal the seam.
Use a bench scraper to transfer the dough, seam-side down, to a banneton or a bowl lined with a clean dish towel dusted liberally with rice flour mixture. It is very important that your towel or banneton are well seasoned with rice flour so that the dough doesn't stick to it.
To do this, you can add layers of flour to the towel or banneton by spritzing lightly with water, applying as much flour as will stick, and letting it dry. Repeat this several times if need be, but let it dry completely before you put your shaped loaf in it.
If the dough is very active and bubbly, immediately place the uncovered shaped loaf in the refrigerator and let it proof overnight. If the dough isn't very bubbly and doesn't feel active, allow it to sit at room temperature, uncovered for 1 hour, and then place the loaf in the refrigerator to ferment overnight.
In the morning gently press the loaf with one finger to see how it responds. If the indentation doesn't bounce back at all, it is ready to go in the oven. If the indentation bounces back just a little bit but you can still see it, it is ready to go in the oven. If the indentation bounces back quickly, let the dough rest, uncovered, at room temperature for another hour.
Preheat the oven to 500°F or as high as your oven will go (an oven thermometer is very useful here as many home ovens are not accurately on temp) and set a Dutch oven inside to preheat as well. If you don't have a Dutch oven, place a pan of water for steam on the bottom rack of the oven.
Place the preheated Dutch oven on a safe work surface (be sure to use oven mitts, as it will be very hot). Place a piece of parchment paper near the Dutch oven and quickly and decisively turn the banneton or bowl onto the paper so that the loaf is centered on the paper. Score the loaf with a baker's lame or serrated knife to a depth of 1 inch in a cross shape. Pick up the edges of the paper and quickly transfer the dough to the Dutch oven. Cover the Dutch oven with a lid and return it to the oven.
After 10 minutes, remove the lid from the Dutch oven to release the steam. Reduce the temperature to 400°F and bake, uncovered, until the bread takes on a dark golden color, about 30 minutes more.
To check the loaf for doneness, knock on the bottom of the loaf and listen for a hollow sound.
When the bread is done, immediately take it out of the Dutch oven and allow it to cool completely on a wire rack before slicing it.
This bread will reach its height of fragrance after cooling down completely, or ideally the next day. Stored in a brown paper bag or wrapped in plastic wrap, it will stay fresh for 3 days at room temperature.