Pies sometimes don’t turn out quite as intended, and cooks both today and a hundred years ago try to figure out why. In a question and answer column in the November, 1921 issue of American Cookery, a reader asked:
Will you tell me in your paper why my Lemon Pies become watery when I return them to the oven to brown the meringue?
The answer was:
A lemon pie may become watery when put in the oven to brown the meringue, if it is left in the oven too long; or it may water because the filling was not sufficiently cooked before putting into the pastry shell, or it may be from an insufficiency of flour being used in making the filling. If you had told us just how your pies are made, we would be better able to answer your question.
A Hundred Years Ago 
Maybe a food torch would solve the problem. Of course, they did not use that back then. My grandmother always made lemon meringue pies.
Interesting. I haven’t made a lemon pie for many years.
My mother solved the problem by giving up on lemon meringue and making lemon chiffon instead.
So many things can go wrong with meringue. But, I’ve had the best results using a Swiss meringue, a lightly cooked meringue, and not over-beating it. Over-beating really destabilizes whipped egg whites in just about any application. You just want to beat the whites to gentle floppy peaks.
My mother made the best lemon pies ever, but always made chocolate more than she did lemon because Daddy liked chocolate better. I preferred the lemon, though! Hers were never watery – now I wonder what she did that kept them from doing that. Now I’m on a search for her recipe to see if there is a clue.
Was that a form of question-dodging?
Kind of a snippy answer, I thought:)
Hehe! Things never change! I really dislike being asked for an answer when I don’t have all the information. I’m glad the response called out the writer of the question…
Mine usually goes watery overnight. The answer to that is probably, eat the pie immediately. Don’t leave any leftovers.
I love Gallivanta’s idea.. 😁 some good sound advice there.