Pies & Pastry tbsp
Pie Filling Thickener Calculator
How much cornstarch for a blueberry pie? About 3 tablespoons for 4 cups of blueberries.
Runny pie? Pick your fruit and how much you have and get the cornstarch, flour or tapioca to use, and for canning, the tested Clear Jel recipe.
How to use it
- Choose the fruit and the cups of prepared fruit.
- Pick your thickener and how juicy the fruit is.
- Toss the thickener with the sugar, then the fruit, and bake until the filling bubbles in the center.
How it works
Swaps follow NDSU Extension: 1 tablespoon cornstarch thickens like 2 tablespoons flour or 4 to 6 teaspoons quick-cooking tapioca.
Blueberries use Ohio State Extension's recipe, 3 tablespoons cornstarch for 4 cups. Other fruits use our starting point, and the page says so.
Canning mode shows the National Center for Home Food Preservation's tested 1-quart and 7-quart recipes with cook-type Clear Jel, unchanged.
Assumptions and limits
- Fresh fruit, sliced or whole berries.
- A double-crust 9-inch pie holds about 4 to 6 cups.
- Cooked until bubbling in the center.
Sources reviewed October 23, 2026.
Tips
- Starch only thickens once it boils: bake until bubbles are slow and thick in the middle.
- Cool fruit pies 3 hours before slicing.
- Frozen fruit releases more juice; use the 'very ripe or frozen' setting.
Recipes to try it with
Questions
How much cornstarch for a blueberry pie?
About 3 tablespoons for 4 cups of blueberries.
Can I use flour instead of cornstarch?
Yes, use twice as much flour. The filling will be a little cloudier.
Can I can pie filling with cornstarch?
No. Only cook-type Clear Jel is tested for canned pie filling.