Prep time: 30 minutes
Total time: a long time
7 cups plus 2 tablespoons|1020 grams King Arthur Special Flour
1 cup|180 grams farmer ground whole-wheat bread flour
6 teaspoons|27 grams active dry yeast
3 tablespoons|27 grams kosher salt
¾ cup|150 grams granulated sugar
4 tablespoons|48 grams unsalted butter (chilled & cubed)
1 ¾ cup|420 grams water, lukewarm
1 cup|240 grams whole milk
2 x 280 grams unsalted butter blocks
1 large egg plus a splash of water, for the egg wash
1. Mix the dough: Scale the milk and lukewarm water into the bottom of a kitchen-aid bowl. Separately scale together dry ingredients, including butter. Pour the dries on top of the wets and use the dough hook attachment to mix on low speed for 4 minutes. The dough will be stiff but still fairly sticky, with a minimum amount of gluten developed. Transfer the dough to a plastic tub coated with nonstick spray and leave to ferment at room temperature for 1 hour.
2. Lightly flour your surface and turn out the dough. Divide it in half - each piece should be approximately 1Kg. Gently shape the pieces of dough into a rectangle and wrap with plastic. Chill overnight.
3. Prepare the fold in butter: use a rolling pin to pound out cold butter to create extensibility without warming or softening. With a half sheet of parchment, fold the short sides to the middle to form a 7" width, then fold the long sides in as needed to form a 9" length. Place the pounded butter inside the parchment envelope, flip it over, and roll from the middle outward towards each corner to make an even slab of butter.
4. Laminate the dough: Temper both the dough and butter packet to 55F before beginning to fold.
5. Lightly dust your surface with flour and roll the cold dough to approximately 14.5" long and 9" wide. Unwrap the butter packet and place in the center of the dough sheet. It should be the same height as the dough. Wrap the left and right sides of the dough around the butter so they meet in the center. Once wrapped, firmly tap the rolling pin up and down the dough package a few times to fuse the two together.
6. Using even and firm strokes, roll the dough lengthwise from the middle upward and then downward. The seam in the center should run perpendicular to the rolling pin. Roll the dough to 24" long x 9" wide. Use a bench knife to trim the ends of the dough until a layer of butter is visible within. Perform a single letter fold (into thirds) and chill the dough for 45 minutes to rest the gluten and cool down the butter.
7. Perform two more single folds at the same dimensions with 45 minutes of rest in between. 3 total folds.
8. Shape the dough: Roll the completed dough to 24" long x 9" wide. Cover with plastic wrap or parchment paper and chill for 20 minutes. Retrieve the dough and correct the dimensions as it will likely shrink.
9. Score the dough at 4" intervals on top and bottom and use a pizza wheel to cut from alternating top score to bottom score to create triangles with a 4" base. Cut a 1" slit in the middle of the base of each croissant. This helps create the signature slight crescent shape of the pastry.
10. Hold each triangle by the base and gently stretch outward by sliding your thumb from the bottom to the tip of the triangle.
11. Use the fingertips of both hands to roll from the 1" slit upward and outward toward the bottom two points of the triangle. Continue rolling upward until the tip of the croissant is tucked under the crescent. There should be 7 steps to each croissant. Transfer to a sheet pan.
12. Proofing and baking: Lightly egg was the croissants before proofing. Let proof for 2 to 3 hours in a warm place (not warmer than 80°F) until very jiggly and a gentle finger poke barely springs back. The croissants should be noticeably larger and inflated with air.
Brush a little more egg wash on the pastries, then back at 400°F for 10 to 12 minutes, or until golden brown.