Not chilling the dough

It is critical to keep the butter cold when making any tart. You must not only start with cold butter, but you must also keep it cold until the crust is baked. You've probably heard that you should chill the dough, but did you know you should double-chill pie dough? Even if you start with ice-cold butter by using the freezer trick, the process of making the dough will warm up the butter. If you roll out the dough right away, you risk activating the gluten. Because butter contains water, and liquid activates gluten, it is critical to keep the butter cold at all times.

After you've made your dough, flatten it into a disc and place it in the fridge wrapped in plastic wrap. Chill the dough for at least 30 minutes and up to 24 hours. The second chill occurs after rolling out the dough. This, once again, has the potential to warm the butter. Chill the dough in your baking dish for at least another 30 minutes before baking.