When you've mixed the pastry, why do you have to leave it in the fridge for half an hour before rolling, baking, someone told me years ago I should do this, but why?
Thanks in advance.
1. when you mix it, the gluten starts to develop in the flour. resting the pastry allows the stretchiness to relax and both makes the pastry more cooperative when lining tines etcetera, it will stay put more easily and less hard and more crumbly when baked.
2. it gives the pastry a cooling period and stops the fat melting into the flour which results in a greasy pastry.
The reason you rest it is so that when you bake it, it doesn't shrink away from the sides of the tin. The gluten in the flour needs enough time to react with the water to become more elastic.