A few months ago I was doing some research on Pie plates and there were a lot of claims that unglazed earthenware made the best pie plates. I was skeptical having heard before that stoneware made the best pie plates and that metal and glass that are so common today really are not good. So I decided to put it to the test. I had already determined that the stoneware plate I had made a better crust than the enameled metal ones I had used before so now I needed to make one from earthenware. So I threw 4 and I gave one to a friend to test, and we tested one. I say "we" meaning Rowan. I didn't peel any apples or make any crust. She made Dutch Apple, and the results were amazing. It's true....the earthenware crust was superior. It was light and flaky and held together nicely while the stoneware one was greasy and messy and didn't hold together well.
I believe the secret is that the earthenware is still quite porous so it absorbed moisture from the crust, keeping it crisp and nice, while the stoneware is vitreous, glazed and doesn't allow any moisture to be absorbed.
These pictures show the difference. It was amazing!