This happened to me yesterday with pâte sucrée, and it has happened before with other kinds of dough too (like the traditional American flaky dough).
When I try to blind bake a pie, I usually do as follows: I lay out the dough over the bottom and sides of an aluminum pan. I then chill or freeze the dough, and once it's sturdier line the insides with aluminum foil, and pour some beans or sugar over it to act as pie weights.
The pan is then set on a preheated oven (about 180°C) and baked. I used to set the pan directly on the oven's grid tray, but as the butter melted it would drip onto the bottom of the oven and burn with an unpleasant smell. I now generally lay the pan onto a baking sheet, and then stick everything into the oven when I want to bake.
Time depends on the size of the pan, but the problem generally shows on larger pans; these are usually circular cake pans (so, vertical side walls) with removable bottoms. For these pans, I bake them anywhere from 45 to 60 minutes.
Now, what happens is that generally the sides of the crust wil brown properly way before the bottom. In fact, the bottom will generally have a soggy aspect, as though the fat in the dough did not cook properly and pooled in the bottom of the crust. The bottom will be almost flexible or sticking to the pan, while the sides will be already crisp.
For smaller tartlets, I can usually remove the foil lining (and even the molds) and stick them back in the oven with good results -- yes, the sides will brown more, but not overly so, and the bottom will turn out okay. For larger pies, this simply won't cut it, and the sides will overcook. I've had good pie bottoms this way, but the sides ended up way too hard.
For these smaller pies I can even stick them back in the oven upside down to really get the bottom going, but this looks like a dangerous game with larger pies. Indeed, the center of the pie's bottom (which is suspended -- the pie is upside down) will become soft in the heat of the oven and bow under its weight. For smaller pies, the distance to the (sturdier) side walls is not so large and this effect is not significant.
So my question is: what's a good way to ensure that blind baked pies brown properly on the bottom without overbaking the sides?
Would convection (in the oven) help or aggravate the problem? Is it a matter of using a lower temperature for a longer time?
Should I preheat the baking sheet together with the oven and set the pan directly onto the hot sheet? Now thinking about it, this should be a no brainer.
Shold I brush the bottom with something before sticking it back in the oven? Egg (whole, beaten? whites? yolk?), or cream? Or something else entirely?
Would other pan materials be better suited to the task (I've been thinking of grabbing a glass pan to be able to see how the crust's browning as it bakes)?
Should I 'shield' the sides of the crust (with foil?) and stick it back in the oven?
Are there other things that could help or solve this?
EDIT: I could salvage the crust and was pretty satisfied with the result. I used aluminum foil to cover the side walls of the pie crust so as to shield it from the heat and hot air currents in the oven.
I placed the pie crust onto the bottom of the cake pan (so, placed it on a solid, thin aluminum disc). I preheated the oven (I used an oven thermometer; it turns out my oven's internal thermostat is not reliable) and, with the fan turned on, placed the disc with the crust onto the oven's grid tray.
Soon enough, the pie crust's bottom/center was bubbling, and in about 10 minutes it had browned lovingly. Moreover, when I removed the foil, the side walls had not browned noticeably more.