Why does my lemon meringue pie get runny?!
Answers: It seens like after I take the pie out of the oven and let it cool it starts to become runny. how do I keep this from accuring?
Pie filling is "runny" most likely because it is not being baked long enough. Simply try baking 5 to 10 minutes longer than normal.
For High-Acid Pie Fillings:
Use tapioca rather than cornstarch to thicken high-acid fillings like cherries and lemons, which can cause cornstarch to fail.
what part is runny? If it is the meringue, it wasn't beaten enough or the oven temp may have been too low. To brown meringue, you need hot oven, quick baking. if it is the lemon filling, not cooked correctly maybe.
Use a bit more cornflour in the filling, and make sure your egg whites are well and truly whisked.