How To Avoid Shrinking Pastries, According To Paul Hollywood - Tasting Table
Briefly

"Overhandling the pastry, either by mixing or touching it too often, will cause the butter to melt and fuse with the flour. Less butter means your pastry has less opportunity to puff when it hits the oven."
"The science behind shrinking pastry begins with the interaction of butter, flour, water, and salt, where the butter's water component transforms into steam as it bakes, creating the necessary layers."
Read at Tasting Table
[
|
]