Pour cool tap water into a stand mixer mixing bowl.
Add your instant yeast and stir it making sure to wet all the yeast granules.
Add your Caputo flour, and your AP flour.
Add Salt.
Mix in a stand mixer until the dough is smooth and pulls away from the edge of the bowl, about five minutes.
Let rise in a covered bowl for 30 minutes.
If making 1 ball, shape, place in an airtight container and refrigerate for 24-48 hours. If not used within 48 hours, you must freeze it. Try to stretch your fermentation as close to 48 hours as you can to get the best complex flavor.
If you are scaling this recipe, say making a dozen balls, I bulk cold ferment all the dough without shaping it into individual balls. Shape the bulk batch of cold mixed dough into individual balls 4 hours before you are going to bake them. As soon as you shape the balls, place them into an oiled container and put back into the refrigerator. Take the dough balls out one hour before baking, letting them rest at room temperature.
Bake for 90 seconds.