I just made a pie with frozen mixed berries and stevia sweetener for the filling. For a 9” pie I normally add two tablespoons each cornstarch, all purpose flour, and white cornmeal to the filling as a thickener, and bake for about an hour and ten minutes at 375 (190 C.) I’ll see how it comes out after it cools off.
My crust recipe: one 6 2/3 ounce stick butter-flavored vegetable shortening (this is about one cup by volume, or 240cc, or about 190g) plus 2 2/3 cups (640cc by volume, or about 340g by weight) sifted all purpose flour, plus one teaspoon (10 cc) each salt, sugar, and apple cider vinegar. I sift together the dry ingredients and cut the shortening and the flour mixture together to form a crumbly mass, then add the vinegar, then just enough cold water to form a pliable dough that can be rolled easily. This makes enough for a top and bottom pie crust, or two individual crusts for 9” (22.5cm) pies.
I normally use about 20-24 ounces by weight of fresh fruit for a pie. This is 570-680g of fruit. Usually I add a little lemon juice and lemon zest, regardless of what kind of pie I am making, because I like the way the flavors combine. Previously I usually added one cup granulated sugar, or seven ounces, 240cc, or 200g, plus the starches. Today’s pie is an experiment with non-sugar sweetener.
Also with soft fruits like berries, I take between one fourth and one third of them and blend them smooth in a food processor, then slowly add to them the sugar and starches. I stir the rest of the fruit into this mixture and use this as filling.
I have a slice of the pie now. It’s not bad. It’s not as sweet as it would have been with one cup of sugar. The label on the stevia sweetener said it was equivalent volume for volume and it doesn’t really seem to be, though I also suppose the berries could have been more acidic than usual. I think it came out well. My doctor says I need to reduce the amount of processed sugar in my diet, and maybe this is a step in that direction.