A simple yeast-risen dough, layered with butter, cut into a triangle and rolled up like a scroll so that the centre bulges and the ends taper out. Traditionally, the unbaked croissant was then curved into a crescent shape, though nowadays croissants are often left straight. Typical ingredients include wheat flour, water, milk, yeast, salt, sugar, butter and egg.
A good freshly-baked croissant should be flaky and crisp on the outside, and tender and moist inside with all the dough aerated and evenly baked. There should be no layers of unbaked dough, and the crust should leave very little buttery oil on the fingers. Packaged croissants tend to lose their crust but when reheated at 180C/350F/gas 4 for 10-12 minutes regain their crisp exterior.
Store croissants at room temperature in a paper bag, to avoid condensation and retain some crispness. For longer storage, freeze croissants, then bake from frozen at 180C/350F/gas 4 for 12-15 minutes.