Creating the Layer Structure

Great care must also be taken when rolling in the butter and turning the dough to get the optimum rise, or puff. If rolled in properly, each layer of dough is separated by a layer of butter. In a hot oven, the moisture in the dough layers produces steam that, if properly sealed in by the butter, will push up as it evaporates. This is how puff pastry rises without the addition of a leavening agent.

Creating an even layer structure can be accomplished only if the butter and the dough have the same consistency, which is why a small amount of flour must first be worked into the butter. As in a bread dough, gluten is formed when flour and water (here, the water in the butter) are combined and agitated. Although not necessary, adding a small amount of citric acid (lemon juice, for example) to both the butter and the dough is beneficial for two reasons: (1) it gives the butter an extra measure of pliability to ensure that it will stretch with the dough as the two are rolled out together; and (2) it tightens the gluten that has formed, as explained above—which in turn helps prevent the finished dough from shrinking.