One of the more colorful accounts of the origin of the croissant is set in Vienna, Austria. In 1683, bakers were working overnight when they heard invading Turkish forces tunneling under the city walls.
They alerted the authorities and the city was saved. To commemorate the event, the bakers created a pastry in a crescent shape-the emblem on the Turkish flag. In fact, the croissant was probably created in France after 1850.
It is best to make enough dough for 24 croissants and to shape all of them, then freeze what you do not need. Freeze the unbaked croissants on a tray, covered tightly with plastic wrap. Ideally they should be frozen for no more than 2 to 4 weeks. Let thaw in the refrigerator before baking.

Dissolve the yeast in two-thirds of the water. Sift the flour into a large bowl. Mix in the dissolved yeast, salt, sugar, very soft butter, and dry milk. Knead everything together quickly. If the dough is still a little stiff, add the rest of the water. Cover with plastic wrap and let rise at room temperature for 1 to 1½ hours.

When the dough has doubled in size,remove it from the bowl and punch it down, then return to the bowl. Cover with plastic again and refrigerate for 1 to 1¼ hours. Remove the dough from the bowl, punch down, cover with plastic wrap, and let rest in the freezer for 30 minutes longer.

Remove the dough from the freezer. Knead the cold butter until it is soft. On a floured surface, roll out the dough to a rectangle three times longer than it is wide. Place half of the butter at the bottom edge of the dough. With the palm of your hand, push the butter up to cover two-thirds of the rectangle of dough.

Fold the rectangle of dough into thirds,folding the unbuttered top third down first. Wrap the folded dough in plastic wrap. Let rest in the freezer for 30 minutes and then in the refrigerator for 1 hour.

Roll out the dough into a rectangle as before and spread with the remainder of the butter. Fold into thirds again and wrap in plastic wrap. Let rest in the freezer for 30 minutes and then in the refrigerator for 1 hour.

Flour the work surface, then roll out the dough to a ⅛ inch (3 mm) thickness. Using a sharp knife, cut out triangles that are 8 inch (20 cm) tall and 5 inch (12 cm) across the base.

To shape, place each triangle with the base nearest to you and roll up, then bring the ends around toward each other to make a crescent. Place the croissants 2 inch (5 cm) apart on a baking sheet lined with parchment paper. Let rise at room temperature for 1½ to 2 hours.

Preheat the oven to 450°F (230°C).Combine the eggs, egg yolk, and salt in a bowl and whisk together. Brush the croissants with this egg glaze, then place in the oven and reduce the temperature to 375°F (190°C). Bake for 20 minutes. Transfer the croissants to a wire rack and let cool.