My neighbors have been calling it the Summer of Pie. As I've researched flaky crusts (both traditional and gluten-free), the ins and outs of tapioca starch in cherry pie, and how to use frozen fruit to amp up the flavor of a classic blueberry pie, I've given away approximately 36 fruit pies—each missing a single slice. For, uh, you know. Science.
The earliest rounds of testing were done in my own cheap-o glass pans, but eventually friends and family just started donating their collections to the cause. Beautiful stoneware, lightweight aluminum, painted ceramic, you name it. And, while each turned out a gorgeous pie, not all produced an equally crispy crust.
Very early on, I discovered that thick ceramic and stoneware turned out pale and greasy crust, even though my pies are baked for about 75 minutes at 400°F. Not that it was much of a mystery; because these heavy materials conduct heat so slowly, the bottom crust bakes more slowly, too. As a result, the flaky butter oozes out of place and never truly cooks through, resulting in a bottom crust that's dense and soft rather than layered and crisp.
This is true of any heavy pie plate, whether it's hand-thrown pottery or lacquered ceramic, so think twice about choosing form over function when it comes to your bakeware. Granted, the greasiness can be mitigated by using a recipe that contains less butter than my own, but comparatively lean and dry doughs are thirsty, eager to absorb moisture from any pie filling, so sogginess will still be an issue with any dough that isn't blind-baked.
My personal choice for pie has always been tempered glass, because it's cheap but sturdy, and nonreactive to boot. Since glass conducts heat more quickly than stone, the butter melts more quickly, too, releasing steam to preserve the dough's flaky layers and turning out a crust that's golden and crisp overall. (The same can be said of thin, lightweight ceramic.)
Despite my deep and passionate love for aluminum in the form of baking sheets, cake pans, and cookware, I'd never actually used aluminum, disposable or otherwise, to bake a pie, because so many recipes (like lemon meringue and Key lime) require a nonreactive plate. Therefore, in my tiny kitchen, it's always seemed more convenient to stock simple glass plates instead.
But I needed to know: If glass is better than stoneware because it conducts heat so fast, does it follow that aluminum is even better?
As a matter of fact, it does. Dirt-cheap disposable aluminum proved to be the greatest surprise of all, baking up an especially crisp and golden crust. While there are some very real logistical difficulties to consider—it will dramatically shorten the time required for a custard pie, invalidating the suggested baking time in recipes based on ceramic or glass—an aluminum pan is without a doubt a fantastic vessel for pie, giving my crust the best browning and texture of all.
Tempered glass is still my favorite overall, due to its sturdiness, nonreactivity, and better-than-average browning, but as I continue to bake and give away a metric crap-ton of pies, there's no doubt that I'll be availing myself of disposable aluminum, knowing that its convenience won't come at the cost of performance.