Durum Semolina with Oat Flour, Potatoes, Yeast Water and SD Starter
Now that I have taken the dive bait and started baking with my Yeast Water Starter, it was time to try something a little more complicated. Following the lead of my friend DA Brownman, I decided to try a combo yeast water levain and AP sourdough levain. To make it interesting I made the yeast water levain using 100% durum flour in a 2 build process and combined this with my existing refreshed AP sourdough starter.
For the final dough I mixed in some Oat flour and some Wheat Germ for nuttiness along with a majority of Durum flour, some mashed potatoes with the skins and some walnut oil.
I have to say that this ended up being a great tasting bread with a wonderful crust and crumb. I'm going to grill some for dinner tonight with some olive oil and grated cheese mixture which I anticipate will be mouth-watering.
Yeast Water Starter Build 1
50 grams Durum Flour (KAF)
50 grams Yeast Water Starter
Mix the flour and Yeast Water in a bowl until thoroughly combined. Cover the bowl and let it sit at room temperature for around 4 hours. The starter should almost double when ready to proceed to build 2.
Add ingredients below to starter from above and mix until incorporated. Cover with plastic wrap and let sit at room temperature for 4 hours.
100 grams Durum Flour
50 grams Yeast Water
Main Dough Ingredients
125 grams Refreshed AP Starter (65% hydration)
250 grams Durum Yeast Water Starter (all of starter from above)
40 grams Roasted Wheat Germ
50 grams Oat Flour
455 grams Durum Flour
161 grams Mashed Potatoes (I like to mash them with the skins on and used red potatoes)
8 grams Walnut Oil
18 grams Salt (Sea Salt or Table Salt)
400 grams Water (80 to 90 degrees F.)
Mix the starters with the water and stir to break it up. Next mix in the flours into the starter mixture and mix for 2 minutes with your mixer or by hand. Let the dough autolyse for 30 minutes to an hour in your bowl covered with a cloth or plastic wrap. Next add in the salt, mashed potatoes and oil and mix on speed #2 for 4 minutes or by hand. The dough should have come together in a ball and be tacky but not too sticky.
Next take the dough out of the bowl and place it on your work surface. Do a stretch and fold and rest the dough uncovered for 10 minutes. After the rest do another stretch and fold and cover the dough and let it rest for 10 minutes. Do one more stretch and fold and put the dough into a lightly oiled bowl and let it sit at room temperature covered for 2 hours. After 2 hours you can put the dough into the refrigerator for 24 hours or up to 2 days before baking. Feel free to do some additional S & F's if you feel it is necessary.
The next day (or when ready to bake) let the dough sit out at room temperature for 2 hours. After 2 hours form the dough into your desired shape and put them in floured bannetons, bowls or on a baking sheet and let them rise covered for 2 hours. Score the loaves as desired and prepare your oven for baking with steam.  
Set your oven for 500 degrees F. at least 30 minutes before ready to bake. When ready to bake place the loaves into your on your oven stone with steam and lower the temperature immediately to 450 degrees. It should take around 20 - 30 minutes to bake until both loaves are golden brown and reached an internal temperature of 200 - 210 degrees F.
Let the loaves cool down for at least an hour or so before eating as desired.