Pie Guide: Thickeners

Pie Thickener

How to make your best filling.

Excitedly slicing into your beautiful baked fruit pie, only to find its luscious filling swimming in excess juice? Wondering if you miscalculated the thickening agent when improvising with your favorite combination of fruits? Ensure your apple, blueberry, cherry, and other baked fruit pie fillings achieve ideal consistency with this helpful guide. 

Please note: The information on this chart may differ from other recipes. If you're following a King Arthur recipe, follow the quantity listed on the recipe for the best results. 

Our five favorites

All-purpose flour is an easy solution, as you’re sure to have it in your pantry. Since it’s lower in starch, you'll use more of it than you would higher-starch thickeners.

Quick-cooking tapioca makes filling bright and clear, but also gives it a stippled and somewhat sticky texture. Filling mixed with tapioca needs to rest 15 to 30 minutes before baking, for the tapioca to soften.

Instant ClearJel keeps fillings thick through a great range of temperatures, making it ideal for pies that are frozen, before or after baking.

Pie Filling Enhancer thickens fruit pie fillings the same way Instant ClearJel does. Its advantage is added ascorbic acid (which adds a bright, tart note), and superfine sugar, which prevents it from clumping. Pie Filling Enhancer is about half sugar, so you'll want to reduce the sugar in your recipe accordingly.

Cornstarch has thickening power similar to Instant ClearJel. Like flour, it lends a cloudy, semi-transparent look to filling. It can also give filling a starchy taste. For full effectiveness, make sure the pie filling is bubbling up through the crust before removing your pie from the oven.

Peach pie filling in a bowl

Apples

Need the least amount of thickener, since they're less juicy. They're also high in natural pectin; pectin helps filling thicken.

Thickener For 1 cup of fruit For one 9" pie (8 cups of fruit)
All-purpose flour 1 3/4 tsp 1/4 cup + 2 tsp
Instant ClearJel 1/2 tsp 1 tbsp + 1 tsp
Cornstarch 1/2 tsp 1 tbsp + 1 tsp
Quick-cooking tapioca 3/4 tsp 2 tbsp
Pie Filling Enhancer 1 1/2 tsp
Reduce sugar by 3/4 tsp
1/4 cup
Reduce sugar by 2 tbsp

Blackberries & Raspberries

Are very juicy, and release even more liquid if they've been frozen; they need more thickener than apples.

Thickener For 1 cup of fruit For one 9" pie (8 cups of fruit)
All-purpose flour 1 tbsp + 1 tsp 1/2 cup + 2 tbsp + 1 tsp
Instant ClearJel 2 3/4 tsp 1/4 cup + 3 tbsp + 1 tsp
Cornstarch 1 tbsp 1/2 cup
Quick-cooking tapioca 1 tbsp 1/2 cup
Pie Filling Enhancer 1 tbsp + 2 tsp
Reduce sugar by 2 1/2 tsp
3/4 cup + 2 tsp
Reduce sugar by 6 tbsp + 1 tsp

Blueberries

These have a lot of pectin; they'll need a little less thickener than other berries.

Thickener For 1 cup of fruit For one 9" pie (8 cups of fruit)
All-purpose flour 1 tbsp 1/2 cup
Instant ClearJel 2 tsp 1/3 cup
Cornstarch 2 1/2 tsp 6 tbsp + 2 tsp
Quick-cooking tapioca 1 1/2 tsp 1/4 cup
Pie Filling Enhancer 1 tbsp + 1 tsp
Reduce sugar by 2 tsp
1/3 cup
Reduce sugar by 2 tbsp + 2 tsp

Cherries

Fresh cherries will need slightly less thickener than canned or frozen.

Thickener For 1 cup of fruit For one 9" pie (8 cups of fruit)
All-purpose flour 1 tbsp 1/2 cup
Instant ClearJel 2 1/2 tsp 6 tbsp + 2 tsp
Cornstarch 2 1/2 tsp 6 tbsp + 2 tsp
Quick-cooking tapioca 1 1/4 tsp 3 tbsp + 1 tsp
Pie Filling Enhancer 1 tbsp + 1/2 tsp
Reduce sugar by 2 tsp
1/2 cup + 1 tbsp + 1 tsp
Reduce sugar by 1/4 cup + 2 tsp

Peaches

Don't have quite as much pectin as apples; they're also juicier, so will require more thickener.

Thickener For 1 cup of fruit For one 9" pie (8 cups of fruit)
All-purpose flour 2 1/2 tsp 6 tbsp + 2 tsp
Instant ClearJel 2 1/2 tsp 6 tbsp + 2 tsp
Cornstarch 2 1/2 tsp 6 tbsp + 2 tsp
Quick-cooking tapioca 1 1/2 tsp 1/4 cup
Pie Filling Enhancer 1 tbsp + 2 tsp
Reduce sugar by 2 1/2 tsp
3/4 cup + 1 tbsp + 1 tsp
Reduce sugar by 6 tbsp + 2 tsp

Strawberry and/or Rhubarb

The juiciest fruits with the least amount of pectin; these will require the most thickener.

ThickenerFor 1 cup of fruitFor one 9" pie (8 cups of fruit)
All-purpose flour1 tbsp + 1 1/2 tsp3/4 cup
Instant ClearJel2 1/2 tsp6 tbsp + 2 tsp
Cornstarch1 tbsp + 1/4 tsp1/2 cup + 2 tsp
Quick-cooking tapioca2 1/2 tsp6 tbsp + 2 tsp
Pie Filling Enhancer2 tbsp
Reduce sugar by 1 tbsp
1 cup
Reduce sugar by 1/2 cup

Tips

Through thin and thick

Unbaked peach pie with top crust half on
  • Remember that fresh farmers market fruit, especially berries, is often juicier than fruit you buy at the supermarket. Adjust your thickener accordingly.
  • Because steam from the filling is able to evaporate more quickly in streusel- or lattice-topped pies, as well as in those topped with pastry cutouts, these require a bit less thickener than pies made with a solid top crust.
  • To prevent your filling from clumping, mix thickener with the sugar in your recipe before adding to the fruit.
  • A just-baked fruit pie’s filling will be very hot out of the oven, and quite messy to serve. The filling will set as it cools; be sure to let your pie cool completely before cutting and serving.