Using a medium bowl, add the water and mix the yeast.
Let the yeast and water sit for about 10 minutes. It should begin to bubble.
Add the bread flour, spent grain and salt.
Using your hand, mix the dough and begin to knead it in the bowl.
Transfer the dough to a lightly floured work surface and knead for about 10 minutes.
Wipe down a medium bowl with olive oil, place the dough into the bowl and turn it to cover it with olive oil.
Cover the bowl with a towel and let it rise in a warm place for 2 or 3 hours.
Bake the Pizza
If you have a pizza stone, put it in the oven.
Preheat your oven to 500 °F.
Punch down the dough. Let it rise for about 30 minutes.
Remove the dough from the bowl and use your fingers to shape it into a 12-inch disk.
Add sauce, cheese, and your choice of toppings.
Bake for 8 to 10 minutes, check occasionally and adjust the time (it will vary with your oven, dough thickness, and toppings). The goal is to have a bubbly top and an evenly browned bottom.