The difference between the two loaves is that the first used 20% hard red whole wheat and the second used 20% white whole wheat flour
Far be it from me to mislead you today by calling the flat bread a true focaccia. I didn't use a biga in the build, I used a sponge of sorts.It does look like a focaccia so I'll give a rambling explanation of what happened and if you decide to follow along, you can name your flat bread a focaccia and I won't call the bread police.
190 g water at 85F
90 g Central Milling AP flour
1/2 tsp active dry yeast
Mix the sponge, cover with plastic wrap, and leave at a warm room temperature for about three or four hours. The surface should have lots of active bubbles.
All of sponge
210 g CM AP flour
Tbs olive oil
6 g kosher salt
2-2.5 g finely chopped rosemary
1-2 tsp coarse sea salt
grated parmesan cheese (optional)
Italian or pizza seasonings
In a small bowl, mix salt into the flour. Whisk olive oil into the sponge, add some flour into the sponge, mix, and add remaining flour. Add the chopped rosemary leaves. Mix with a dough whisk or wooden spoon to a shaggy mass. Cover and rest the dough for about twenty minutes and then turn the dough with a bowl tool for about thirty strokes. Cover and rest for another twenty minutes then turn again. Cover and rest for twenty minutes then turn the dough out onto a lightly floured surface. Quickly wash and dry the bowl then oil it with a little olive oil. Knead the dough for about a minute and place back into the bowl and cover. If the dough is still slack a stretch and fold or two should bring it to reasonable strength, for a flat bread, and then rest, covered, until it doubles in size.
Oil a jelly roll pan and place the dough into the center of the pan. Slowly stretch the dough, striving for a rough evenness, out to the corners of the pan. If the dough resists, cover it with a towel, wait ten minutes, and stretch again. Cover and let the dough rest at room temperature until it gains some height, 45-90 minutes depending on temperature.
Preheat the oven to 450F. A baking stone can be used when baking with the pan. I've done with and without, its the baker's choice. When the dough has risen and the oven warmed up, dimple the dough with your fingertips. Drizzle some olive oil on the dough and make sure that all the dimples have some oil in them, Sprinkle with the cheese if your so inclined and then the sea salt.
Load the pan into the oven on a middle rack. Turn the pan after ten minutes. Check the pan for color at the twenty minute mark. If its nice and golden, you're good, take the pan out. If not, your flat bread should be done at the twenty five minute mark. Remove the flat bread and cool on a wire rack. Serve as soon as possible after baking. Freeze leftovers, if there are any.