Method: Create a liquid starter, a poolish, by mixing the water with the yeast. Cover the water and yeast mixture with the first amount of pastry flour (4.8 ozs.), and let it ferment until cracks form on the surface of the flour. The advantage of the poolish is to obtain a more natural fermentation, which results in a more developed flavor. It is important not to disturb the poolish. Mix the salt, sugar, soft butter and milk in a small bowl. Then, add the flours and the salt/sugar/butter mixture to the poolish. Mix with the hook in first speed for one minute. Do not over mix. Transfer the dough to another container, and cover with plastic wrap. Place in a 75°F (24°C) proofer, and let the dough rise for about 30 minutes until it doubles in volume.

Remove the dough from the proofer, and press out the first gasses. Then, place it in the cooler until very cold. Scale 1 lb. (460 g) of butter, shape it into a square, and place it in the cooler. Sheet the dough into a square with the middle thicker than the edges (about the same thickness as the butter). Place the dough in the freezer for about 30 minutes before laminating the butter. Place the square of softened, but still cold, butter on the dough. Fold the dough over the butter, and place it back in the cooler until both are the same temperature. Sheet the dough into a rectangle (three times as long as it is wide), and give two single folds. The key to this procedure is to make sure that the dough and the butter are cold yet still pliable. Butter that is too cold will crack and break in small lumps, and butter that is too soft will promote the lamination of a singular dough.

Place the dough in the freezer for 30 minutes or refrigerate overnight. Sheet the dough into a rectangle and give one single fold for a total of three single folds. Sheet lengthwise to a 1/8-in. thick rectangle. Divide the dough into two even strips with a knife. Cut uniform triangles (each at 1.75 ozs. or 50 g) out of each strip. Stretch each piece slightly prior to rolling the croissant. Place 20 croissants on each sheet pan with the tips towards the center of the pan so they do not burn. Egg wash the croissants lightly, but not the edges. Place the croissants in the proofer at 82.4°F (28°C), 85 percent humidity until they double in volume. Take them out, and let rest for 15 minutes. Egg wash again. Bake at 356°F (180°C) for 6 to 7 minutes in a convection oven with the vent closed or for 6 to 7 minutes with the vent open.
Yields 24 croissants