Friday, December 12, 2008

The Riddle of the Runny Pie

Nothing can be more embarrassing than to make a beautiful custard pie and, when you cut into it, to discover the filling, that was just the right thickness when you poured it into the beautifully browned crust, has now turned into a runny liquid mess! You've made that pie a hundred times and are sure the ingredients were fresh and accurate. Well, my friend, you have been visited by the enzyme amylase thieves! These sneaky little culprits, who live in the yolks of eggs, have gobbled up all the starch in your pie.

Egg yolks must reach a temperature of over 140 degrees F or the thickening they provide actually reverses itself due to the enzyme amylase in them, which attacks the starch, unless it's deactivated by adequate heat. In other words, you must bring the custard to a boil to destroy these enzymes. I realize it's much easier to cook custard in a double boiler, which allows you to do other things at the same time because you don't have to stand over it to keep it from scorching. But you have to bring it to a boil and the double boiler will just not let you do that.

When I make a cream pie I put all but 1 cup of the milk that is required into a pot and let it start to heat up as I mix the sugar, egg yolks and cornstarch together. Then I add the cup of cold milk to the egg yolk mixture and, while whisking constantly, slowly pour that into the heating milk. I continue to stir with a whisk until the custard comes to a boil and is thick. Then I remove it from the heat and add the butter and flavoring and pour it into my already browned crust. I quickly beat the whites for the meringue and pour them on top of the hot filling, making sure it touches the crust all the way around. Then I bake the meringue at 350 degrees F. for 25-30 minutes or until nicely browned.

No comments: