Blind baking is done by lining a pastry shell first with parchment paper and then with some kind of weights to ensure that the bottom stays flat and the sides upright.
I have seen recipes that use rice, lentils, beans or even ceramic pie weights. And apparently all of them work. But does the choice of weights matter? Is there a difference e.g. between rice (small grains, each comparatively light) and beans (larger heavier beans)? Has anyone tested this?
Best Answer
What matters is keeping the crust from puffing and pulling away from the pie plate or tart mold. So any of those work...more or less the same, but the typical drawback is that it is difficult to keep the sides of the crust in the proper form. One of the most ingenious ways to deal with the issue is to line your pie plate with dough, place parchment on top, place an empty pie plate on top of that. Now flip the whole thing over so that the empty pie plate is on the bottom (placed on a cookie sheet). The dough is now baking upside down on top of the empty pie plate (leave everything in place, so that the dough is between plates with parchment while baking)...no shrinking or puffing. Also...a well-chilled dough helps. You can even form, then return to the fridge for a while to chill before baking.
Edit after question in the comments: The question from @Alex led me to revisit the origin of this technique, which I recently heard about on Dave Arnold's radio show, "Cooking Issues." It comes from a book called Pie Marches On by Monroe Boston Strause. It can be found online. It does not use two pans as I originally thought, rather, he blind bakes on the bottom side of one pie tin. Then flips onto a shallower pie tin for cooling and filling.