Put wheat flour, sugar, salt, eggs and yeast in a food processor, add milk a little at a time and process until the dough becomes quite hard (about 4-5 minutes). Then work in the soft butter at medium speed, increase the speed and run for a few more minutes. Put plastic over the bowl and allow the dough to ferment overnight in the fridge.
Take the dough out of the fridge and turn it up on a lightly floured baking table.
Beat out the butter with a floured bread roll to a square, about 20 × 20 centimeters.
Roll out the dough to a square, about 32 × 32 centimeters. Place the butter in the middle and fold the edges towards the center, rolling out to a rectangle. First fold one side towards the middle and then the other, rolling slightly. Wrap in the dough and let it rest in the fridge for 1 hour. Repeat this three more times.
Then roll out the dough until it is 45 × 45 centimeters and about 3–4 centimeters thick. Cut out triangles, about 12 inches high and 12 inches wide. Roll up the croissants, starting with the wide side. Bend the edges and shape into a crescent.
Place the croissants on a sheet of baking sheet paper and brush with whisked egg mixed with a little salt and water. Place a low saucepan of hot water in the bottom of a switched-on oven and insert the plate. Beat for 2-4 hours until the loaves become twice as large. Remove plate and saucepan.
Set the oven to 220 degrees. Brush one more time and then bake in the middle of the oven for 15-20 minutes. Take out and let cool on grill.
If you want dark “French-fried” croissants, you can increase the heat to 240 degrees in the last minutes, but then keep a little watch so that they do not get burnt.
