In a large bowl or the bowl of your stand mixer, combine water and sourdough shortly. Add olive oil, all flours, salt and mix for a few minutes until well combined.
Let rest for about 15 minutes.
Knead the dough, either by hand for about 10-15 minutes or with the dough attachment of your stand mixer, or with Thermomix, for 8 minutes, low speed. Look at the video to get an idea of the dough once it's done kneading.
Put the dough ball in an oiled bowl (use olive oil), cover and let rise for about 4-5 hours. This step could take less time, depending on your house temperature, strenght of your sourdough or flour. The dough does not have to rise to double the size but it does need to get slightly puffy. There is a longer rest in next step.
Once the first rest if over, cut the dough in 4 parts and roll each part into a ball (see video). Either wrap each dough ball in plastic or wax wrap or put in am oiled container and cover (this our preferred method).
Rest in the fridge or cold room or garage, ideal temp of 6-10C (42-50F) is desired.
About 2 hours before your planned pizza cooking time, transfer the balls to room temperature. If it is really hot in your house, reduce this time to 1 hour. It's ok if the ball spread a little but if you see the surface of your dough balls starting to tear, it means you have over proofed your dough balls and should aim for shorter rest times in the future.
Start your Forno Venetzia oven! We are aiming for 650-675F floor temperature and about 600-650F oven temperature. You can cook your pizzas at higher temps but we suggest starting in these temperatures to get used to the process.
Notes
The higher the oven temperature, the less hydration your dough needs so you'll want to cut the water in the recipe (reduce by about 5% total hydration or 35g water - for total of 265g water in the dough recipe - for 850-900F cooks).