Puff pastry

Puff pastry

Puff pastry before baking, with layers clearly visible
Alternative names	Water dough, détrempe, pâte feuilletée
Type	pastry
Place of origin	France
Main ingredients	Butter, flour, water.

Puff pastry, also known as pâte feuilletée, is a flaky light pastry containing several layers of fat which is in solid state at 20 °C (68 °F). In raw form, puff pastry is a laminated dough composed of two elements: a "dough packet", the détrempe and a "butter packet" or other solid fat, the beurrage. Preparing a classic puff pastry requires an envelope formed by placing the beurrage inside the détrempe. An "inverse puff" pastry envelope places the détrempe inside the beurrage. The resulting paton is repeatedly folded and rolled out before baking.

The gaps that form between the layers left by the fat melting are pushed (leavened) by the water turning into steam during the baking process. Piercing the dough will prevent excessive puffing, and crimping along the sides will prevent the layers from flaking all of the way to the edges.

Puff pastry seems to be a relative of the Middle Eastern phyllo, and is used in a similar manner to create layered pastries. While traditionally ascribed to the French painter and cook Claude Gelée who lived in the 17th century (the story goes that Gelée was making a type of very buttery bread for his sick father, and the process of rolling the butter into the bread dough created a croissant-like finished product), references appear before the 17th century, indicating a history that came originally through Muslim Spain and was converted from thin sheets of dough spread with olive oil to laminated dough with layers of butter, perhaps in Italy or Germany. Culinary educator Robert Wemischner states that the first printed recipe was published in François Pierre La Varenne's "Pastissier francois" in 1653.

The production of puff pastry dough can be time-consuming, because it must be kept at a temperature of approximately 16 °C (60 °F) to keep shortening from becoming runny, and must rest in between folds to allow gluten strands time to link up and thus retain layering.

The number of layers in puff pastry is calculated with the formula:

where ${\displaystyle l}$ is the number of finished layers, ${\displaystyle f}$ the number of folds in a single folding move, and ${\displaystyle n}$ is how many times the folding move is repeated. For example, twice-folding (i.e. in three), repeated four times gives ${\displaystyle (2+1)^{4}=81}$ layers. Chef Julia Child recommends 73 layers for regular pâte feuilletée and 729 (i.e. 3⁶) layers for pâte feuilletée fine (in Volume II of her Mastering the Art of French Cooking textbook).