Biga

149 g unbleached all-purpose flour 113 mL cool water (75.8%) 1/8 tsp instant yeast

Dough

All of the biga 482 g unbleached all-purpose flour 340 mL lukewarm water (71.8% overall) 1 tsp instant yeast 2 tsp salt

Recipe

  1. Mix the biga in a small bowl. Don't knead it; just make sure all of the ingredients are well-incorporated. Set this mixture aside in a warm place, covered, and let rise for 16-24 hours.

  2. Mix the dough ingredients in a stand mixer until the dough passes the window-pane test, about 10 min.

  3. Cover the dough and let it rise in a warm place for 2-3 hours, gently performing a drop-hook fold (mix with the dough hook for a few seconds, flip the dough over or on its side, mix again for a few seconds, then cover and let continue rising) 4 times in total.

  4. Scoop the dough onto a lightly greased pan in two separate pieces. Shape each piece into a rough oval as best you can.

  5. Cover the dough with greased plastic wrap and let rise for another 90 min.
    It'll spread out quite a bit.

  6. Bake at 450°F for 25-30 min, or until the crust is golden brown.

  7. Turn off the oven, then move the loaves onto one of the oven racks and allow them to cool in the turned-off oven.

How to get an open crumb

  1. Don't manipulate the dough too much.

    Most breads have 2 fermentations: bulk one and proofing. Do just one. The more you handle the dough, the more you will degas it by breaking bubbles and letting the gas escape the dough.

  2. High hydration

    With more water the dough will be less stiff, so bubbles will be able to extend more. Also, it will be easier for the yeasts to "find" their food: sugar, so they'll produce more CO2 and alcohol.

    Be aware that some flours absorb more water than others. By using a flour with high absorption index, you may be able to get higher hydration without to dough becoming too runny to work with.

  3. Yeast and time

    The more yeast you add, the more gas will be in the dough. But don't add too much or they'll run out of food and die before baking. It's better to give them time to do their work.

  4. Use strong wheat flour

    The more time dough is waiting to be risen, the more gluten will be destroyed by enzymes. So using flour with a lot of gluten (strong, high % proteins, a W value over 270) will help assuring a minimum of gluten will still exist after long fermentations.

  5. Oven spring

    Yeasts continue producing CO₂ until they die at 140°F (60°C). Also, gasses expand with heat, so it will also help holes to grow a bit (if I remember well, up to 30%). But that growth will stop when dough gets baked and strengthens, and when crust begins to form. You can use these three techniques to delay the formation of the crust:

    • Use steam in the oven the first 1/3 or 1/4 of baking time. Steam will keep the "outer skin" of the bread humid, so it will prevent it from getting dry and forming the crust.

    • Score the bread (i.e. make cuts on its surface) to allow the outer crust to crack and expand a little more.

    • Use a baking stone to allow heat enter in the dough from the bottom up.

  6. Develop the gluten completely

    Kneading is very important, so the gluten network will perfectly developed to retain all the CO2 and alcohol.

    To get high hydration doughs, bakers sometimes make a normal hydration dough (approx. 66%) with all the flour, and then add the rest of water and knead a bit more to let it absorb it.

Fun facts

  1. Amylase is found in flour. Wheat kernels contain amylase because they need to break starch down into sugar to use for energy when the kernels germinate. The amount of amylase varies with the weather and harvesting conditions of the wheat, so mills generally test for it and add extra or blend flours to get an appropriate amount.

    Amylases are mobilized when water is added to the flour. This is one reason why doughs with a higher hydration often ferment faster: the amylases (and other enzymes) can move about more effectively.

  2. Proteases occur naturally in flour, yeast cells, and malt. Their levels are measured at the mill and adjusted in the same way that amylase levels are adjusted.

  3. Bleached flour is treated with chlorine gas. This treatment increases the amount of protein in the flour that is water soluble (Tsen, Kulp, Daly.
    Effect of chlorine on flour proteins, dough properties, and cake quality.
    Cereal Chem. 1971. 48:247-254). This effect is hypothesized to be the result of chlorine cleaving peptide bonds and breaking the gluten proteins into fragments that are shorter more water-soluble.

    Chlorine also reacts with the water in the flour to produce hypochlorite (bleach), a free chlorine ion, and hydronium. This is why bleached flour is more acidic (pH 4.5-5.2) than unbleached flour. However, this is not how chlorine affects gluten formation, because the gluten network is weaker even after the pH is restored by the addition of chalk.