Overripe apples release too much moisture during baking.

Not using enough thickening agents like cornstarch or flour.

Cutting apples too thinly causes excessive water loss.

Not pre-cooking the filling leads to excess liquid in the crust.

Adding too much sugar increases moisture release.

Skipping the rest period after tossing apples with sugar and spices.

Using the wrong apple varieties that are too watery.

Baking at a low temperature results in poor evaporation of liquid.

Not sealing the pie crust properly allows liquid to escape.