Why does pastry shrink?

Answer 1

One of the main reasons pastry shrinks is because it has been overworked, try to ensure all your ingredients are cold, use the minimum amount of work to bring the ingredients together, then allow your pastry to 'rest' for 30 mins in a cool area or fridge before you roll it, again minimum amount of rolling. Your pastry should be virtually shrink free.

Answer 2

Pastry needs to "relax" before being baked. Depending on your pastry type the pastry should relax for a minimum of 60 minutes, but often best to "relax" it overnight. The "rest" time the gluten that has been developed , this facilitates rolling and prevents shrinkage. When placing in the "chiller/fridge", do not wrap it in a cling wrap or plastic wrap as this allows for the absorption of water. An increase in water means an increase in the production of gluten which will cause "tough" pastry.

Answer 3

When the cake is hot, vapors are still being emitted and expanding the air pockets in the cake. As it cools, these vapors escape and the air pockets collapse some, making the cake appear smaller.

Answer 4

if your cake's shrinking, then you're doing something wrong...your cake should be rising due to the chemical reaction of heat and baking powder.