The Birkmann ceramic pie weights are important for a perfect pastry crust. These small ceramic balls, serve as a temporary filling during the first round of baking. They’re not extremely heavy, but they’re substantial enough to weigh the dough down enough to prevent puffing. It’s all chemistry! As the dough bakes, the fat melts at a different rate than the rest of the ingredients. This is a good thing because steam is responsible for the flaky layers you associate with a perfectly prepared pastry crust. When there is no filling to weigh it down, steam will cause the crust to puff up and deflate, leaving a wrinkly mess that is not fit for filling. So next time you are preparing, be sure to use these ceramic pie weights for that perfect pastry crust. Sufficient for a 28cm/11” pan.