Silicone and Cindy Crawford: How it Relates to Your Tart

Dear Tricia, I've recently acquired a silicone dish for baking pies, tarts, cheesecakes, etc. I must say, it works pretty well, but I've noticed a big difference concerning the crustiness of some of the things I bake. For example: I like to make a kind of salty tart out of a crust (pâte brisée), tomatoes, mozzarella and dijon mustard. With the tomatoes, you can imagine that I have a hard time keeping the "wateriness" to a minimum. When I use the silicone dish, the tart comes out pretty darn watery, but with a glass or metal dish, the water seems to disappear! The question is this really: What is the real difference between silicone dishes and normal baking apparatuses (I know that's latin based, so it's gotta be apparati or something stupid like that)? Are the pros and cons for each one aside the obvious "crustiness" that comes from using normal baking dishes?

Ooooh, I love this one. Mostly, because it involves physics and I'm always trying to up my game in that department. After much research, I couldn't find the information I needed in relation to baking dishes, so I emailed my favorite chef, Peter Greweling, who is my mentor, my former instructor, and author of Chocolates & Confections, and the recently released Chocolates and Confections at Home. He also loves martinis, so we share that priceless connection.
A baking dish basically serves two purposes: to hold the batter or dough, and to transfer heat from the oven to the product inside of the baking dish. When its transferring heat, that's called "conducting." Lets talk about conducting heat: remember that topic in elementary school? Everything conducts heat. Good heat conductors are metals: think aluminum foil, iron, steel... things that baking dishes are often made out of. Glass? Eh... its okay. Silicone? Not awesome. Imagine holding a two cups of super hot coffee, one is made out of aluminum, and one made out of silicone. Which one is going to burn your hand faster? The aluminum one, because it conducts heat better, or transfers the heat to you faster.
Lets apply that to baking dishes. An aluminum or steel tart pan is going to take the heat from the oven and transfer it to the tart dough super fast. That, in turn will caramelize the sugars in the dough really well, brown the proteins in the flour like a champ, and give you a brown and crusty finish. Because your silicone baking pan, though convenient to use (we'll get to that in a minute), doesn't conduct heat very well, its going to give you a less crusty and lighter colored tart if you baked it at the same temperature. The same idea applies to the watery tomatoes inside the tart. The heat is being transfered throughout the entire product and the idea is to make the water in the tomatoes evaporate, but if its not getting enough heat to do that, the water will just hang out and create a sog party. Gross.
Silicone baking dishes are a newer revolution in the baking world. For gazillions of years, we've been baking things in metal pans. But this new idea of silicone pans is great because they're flexible and things don't stick to them, so you can literally peel the cake pan off a cake without having to bang it on the counter top to get it out. Tart pans are notorious for being little assholes. You put all that work into your gorgeous tomato tart creation, but if the crust sticks to the sides of the pan, it breaks and cracks and disappoints everyone and ruins dinner. So I get why silicone tart pans are ideal. It may give us cancer 50 years down the road and we end up with PVC pipes as intestines, but oh well... it's FDA approved and they know everything about everything, right?
So, back to your dilemma. All you really need to do is turn up the temperature of your oven to create more heat. If the recipe says 375 degrees, go up to 425 and see how it does. If the tart fillings start to dry up too much, put a piece of foil over them to keep them covered until the crust is finished... or you could just turn the oven down a little at that point: whatever works for you.
Lets summarize today's physics lesson. Metal baking dishes are like the Cindy Crawford of baking dishes: if heat was makeup, she don't require a lot of it to be smoking hot. Silicone baking dishes are like Sarah, Plain and Tall: sure, she's practical and efficient, but she needs a hell of a lot more makeup to get to Cindy Crawford's level, doesn't she?