Add the brown rice flour, oat flour, potato starch, and tapioca flour to a small mixing bowl. Whisk to combine and set aside
80 g potato starch, 60 g tapioca flour, 80 g gluten-free oat flour, 106 g brown rice flour, 8 g salt
Add the sugar to a 2 cup measuring cup. Then add the warm water and psyllium husks. Whisk immediately to let the psyllium form a gel. Let set for 5 minutes.
20 g sugar, 20 g whole psyllium husks
Add sourdough starter and avocado oil to a large mixing bowl or the bowl of your stand mixer.
300 g active gluten-free sourdough starter, 10 g avocado oil
Add the psyllium gel to the starter and avocado oil. Whisk to fully combine.
Add the dry ingredients to the wet ingredients and use a dough whisk to loosely combine. Then, either bring it together with your hands or use a stand mixer to combine using the paddle attachment. It is ready when no dry flour remains in the bowl.
Turn the dough out onto your counter and shape into a smooth ball. Place the dough seam side up into a 7 inch banneton that has been dusted with white rice flour. Place into a large zip-lock bag or cover with a shower cap. Let sit at room temperature for 30 minutes - 1 hour. In the warmer months use the shorter time and in colder months use the longer time.
Place the banneton in the refrigerator for 12 - 16 hours.
When you are ready to bake, place your dutch oven in the oven and preheat to 500℉. Set a timer for 1 hour.
Turn the dough out onto a piece of parchment paper and score as desired.
Place the dough in the hot dutch oven and immediately turn the temperature down to 450℉. Bake for 35 minutes. Take the lid off and turn the oven down to 400℉. Bake for 30 minutes. Turn the oven down to 350℉ and bake for a final 30 minutes. Turn the oven off and wait 10 minutes to take the bread out of the oven.
Let the bread cool on a wire rack for at least 4 hours before cutting it.