Remove the biga from the refrigerator 1 hour before making the dough. Cut it into about 10 pieces and cover with a towel or plastic wrap and let sit for 1 hour to take off the chill.
Mix together dry ingredients. Add biga, olive oil, and 3/4 cup water, and mix until a ball forms. Add additional flour or water as necessary. Dough should be slightly sticky and soft, but it's better for it to be too wet than too stiff because it will absorb additional flour as you knead.
Place dough on floured surface and knead for about 10 minutes, adding flour as necessary, until dough is tacky and soft, but not sticky. The dough should pass the windowpane test. Place in an oiled bowl, coat with oil, and cover with plastic wrap. Ferment at room temperature for about 2 hours or until dough doubles in size. If your kitchen is anything like mine or my mom's, you may need to put your dough in a warmer place.
Gently divide the dough in half, deflating the dough as little as possible. (That said, I degassed my dough a lot, and it didn't harm it at all.) Shape the dough into batards, which are torpedoes or shortened baguettes. Gently pat dough into a rectangle. Without degassing the dough, fold the bottom third of dough, letter style, up to the center and press to seal, creasing surface tension on the outer edge. Fold remaining dough down over the top and use the edge of your hand to seal the seam closed and to increase the surface tension all over.
Let the dough rest for 5 minutes to let the gluten recover, and then stretch the loaves out to about 12 inches in length. You're supposed to put the dough on a baking sheet dusted with flour or cornmeal, but I just put the dough directly on the baking sheet. Coat the loaves with oil, cover with plastic wrap, and let proof for about an hour, or until loaves have grown to about 1 1/2 times their original size.
Preheat oven to 500F and place an empty pan on the bottom rack of the oven (so you can pour water into it later to make steam). Score the bread - I tried a single long slash, but I didn't really go deep enough, unfortunately.
I baked my loaves directly on the sheet. I didn't have a spray bottle, so I sprinkled water on the loaves, which made the crust blister a little but didn't hurt the bread. I put the loaves in the oven on the middle rack, and poured hot water into the hot, empty pan on the bottom rack. I lowered the temperature to 450F and baked the bread for about 20 minutes, rotating the loaves once. At 20 minutes, the bread was golden brown and done! I didn't cut the bread until the next day when we made garlic bread.