Two apple pies, two very different results: help me understand.
A family member has gone vegan and I am experimenting with vegan apple pie to make at thanksgiving.
I bought 2 frozen vegan/whole wheat pie crusts (ugh, I know - suggestions welcome on the crust options - no walnuts/pecans though) and sliced up granny smith apples for two pies. I mixed all the apples according to the recipe for "butterscotch apple pie" in the current Gourment magazine special: lots of brown sugar, cinnamon, touch of salt, lemon juice and vanilla.
One difference in the filling: for Pie # 1 I mixed in a small amount of white flour, for Pie #2 I mixed in the equivalent amount of cornstarch (half as much, according to the equivalent info on the cornstarch box.
For Pie #1, I pre-baked the crust on the bottom, then piled in the apples and put an oatmeal streusel/crisp-like topping (rolled oats, cinnamon, maple syrup, canola oil) on top. For Pie# 2 I just piled the apples directly into the pan and lay the crust on top and sprinkled it with granulated sugar (I hate soggy crust and thought this might make it better.
Cooked both for close to an hour at 400
The surprising results:
Pie #1: (Crust on bottom, oatmeal on top, flour in filling) Crust on bottom was delicious, not too soggy, in fact better because it had absorbed some apple-cinnamon deliciousness. Oatmeal crisp on top was not so great, dry/burned a little. Apples were cooked but not well-cooked/caramelized.
Pie #2 (crust on top, cornstarch in filling): apples underneath had cooked way way down into an amazing caramelized tarte tatin-like substance. Crust on top was ok, but a little bland and maybe too separate from the apples. Like a cookie on top of caramelized apples.
What explains the difference in the apples, and how do I get the best of all possible worlds? My theory -crust on bottom insulates apples more, so they don't cook down as much? My current plan is to pre-cook/caramelize a ton of apples before putting them in a slightly pre-baked crust and then cooking a little longer as a pie just to meld the two. Will skip the streusel topping which added nothing interesting. Maybe a lattice if I get ambitious?
I don't know what the science behind this might be, but I generally find that streusel pies take longer to bake than crusted ones. I usually pack my streusel on pretty thickly, so perhaps it insulates the apples more than a crust does? It could also be the opposite - the streusel lets out more moisture than the crust does so the apples don't have a chance to steam in their own juices?
Did you use identical pans for baking? Were they on the same rack in the oven, baked at the same time?
More info before we can sleuth this out, but one of the tricks in baking apple pies is to find a way to keep the liquid from sogging up the crust. Some people prebake the crust, some slightly pre-cook the apples so that the liquid can thicken before touching the crust.
When I am making multiple apple pies, which is most of the time, I fill the crust with the spiced apples, then measure the amount of juices in the pan and put an equal amount in both. Sometimes I discard about half of the spiced juice because it is too great an amount and would just make a gloppy pie. As a thickener I use half flour and half cornstarch because it gives a nice, clear cooked fluid.
400 is too hot. 375 is better. You want the crust to brown, but not so fast that the apples aren't well-cooked. Put a sheet pan in your oven while preheating, then place the pie tins upon it.
That quick-starts the baking of the bottom crust and helps prevent it from being soggy. I line the sheet pan with parchment, so if the filling bubbles over, there's no scrubbing needed. Consider tapioca as thickener - whirl it in a food processor. It makes a much nicer thickener than flour or cornstarch. So does arrowroot. Clear, but a little gel-like rather than saucy.
There's more than one way to skin a cat - and an apple.
I always bake apple pies at 425. Pie crust needs to cook at a very hot temp. I've never precooked the bottom crust and have never had a soggy pie. But then again, I take the time proven step of parcooking the apples, sugar, spices and thickener. It helps the filling thicken properly and cook through.
I don't whirl the Minute tapioca (pie recipe is on the Minute tapioca box), but I do make sure the tapioca spends 10 minutes soaking into the apples to soften it. Flour works just fine as a thickener too. I made six apple pies the other day using flour as the thickener - parcooked the apples, sugar, flour and spices, every pie came out perfect. I Like to brush the top crust with a little milk. Some folks like an egg wash (which makes a shiny crust if that's what you like).
Here's a link showing how my mother in law makes a delicious flaky apple pie:
Even though you used the same type of apples, the top crust of the two pies are different, therefore giving you different results. The one with the regular pie dough seal the apples causing them to steam more and cook faster than the one with the streusel. The one with the pie crust on top will usually have a space between the crust and apples after baking. That is due to the fact that apples do not collapse as with other fruits during the first part of baking while the top crust sets.
Because streusel topping usually contains more sugar, it will brown much quicker. Bake it at a lower temperature for a longer time to cook the apples to your liking. If your streusel is getting too brown, just tent it with a sheet of foil and continue baking.