You create the perfect pie, cut a slice and realize it’s way too juicy. What happened? The recipe didn’t call for enough thickener. Chances are the recipe didn’t even mention adding a thickening agent. Most fruits have high water content. Baking releases the juices from the fruits and ends up creating a jammy, juicy filling that you didn’t expect. The more juice the pie contains, the more likely the bottom crust will become soggy.
When it comes to pie thickeners, old world meets new. Many recipes created years ago recommend using all-purpose flour, cornstarch, or tapioca. You’re not going to find a recipe created in the early 1900’s that mentions using Xanthan gum or Clearjel because they didn’t exist when the recipe was formulated. In today’s world we want to use the best thickener that creates the end result we’re looking for -filling that doesn’t fill the entire pie plate with juice when you cut the first piece.
As with most piemaking techniques, sometimes you need to test a method and tweak the recipe based on the results. For decades I used 1 tablespoon of all-purpose flour in my apple pies. They were runny but everyone devoured the pies so I didn’t change a thing. Then one day I ran across an apple pie recipe that recommended 1/2 cup of flour. I tried it and my food critics (friends and neighbors) said it wasn’t very juicy. I made the next pie with 1/4 cup of flour and have been receiving rave complements every since.
Below are the most common pie thickening ingredients use for making fruit pies. There are several others available that aren’t as well known but most can be purchased only from the company’s website. I prefer to use and recommend common products that can be found just about anywhere.
Most Common Pie Thickening Ingredients
All-purpose flour
Flour is by far the most used pie thickener with the weird exception of cherry pies. For some reason nearly every cherry pie recipe I’ve ever looked at recommends tapioca as the thickener. All-purpose flour is the easiest choice since you probably already have it in your kitchen
Cornstarch
Like flour, cornstarch gives the filling a semi-transparent look. One of the drawbacks is that it can also give the filling a starchy taste. I personally have never used cornstarch in a pie but many recipes call for it. My best suggestion would be that the cornstarch is as well blended into the other ingredients as possible. If using cornstarch, make sure you can see the pie filling bubbling through the crust before removing it from the oven
Instant Clearjel
Instant Clearjel is difficult to research because there are multiple brands that offer a similar product under different names. You might find it spelled Clear Jel or Clear Gel. Clearjel thickens pie fillings and adds texture. Using the product is as simple as mixing it with the sugar. It is especially useful when preparing pies in advance and freezing them to bake later. My mother makes 12-15 apple pies every fall when the orchards are ripe with her favorite apple. She prepares the pies then freezes them in resealable bags. When she feels like baking one she takes it out of the freezer and slides it directly into the oven.
Instant Tapioca
Tapioca seems to be a holdover from previous generations. I know only one person who actually like tapioca. Most recipes you find calling for tapioca were probably created by someone who loves it. Tapioca will give your pie a somewhat sticky texture. It’s almost like overcooked oatmeal but not quite as thicken. If you use tapioca in a pie, it’s important to remember that the tapioca needs tto soften before adding to the filling. To soften the tapioca it must rest 15 to 30 minutes at room temperature.
Common Types of Fruit Pie Fillings
The recommended amounts of the thickeners mention below are based on an average of 8 cups of fruit going into a 9-inch deep dish pie plate.
Apples
Since apple is the #1 most popular pie in America, apples are obviously the most used pie filling. Most apples are less juicy than other fruits and require the least amount of thickener. They are high in natural pectin, which helps thicken the filling as it bakes. I personally add 1/4 cup of all-purpose flour to my apple pies and the results have never been disappointing.
Amount of Thickener Recommended
- All-purpose flour – 4-5 tablespoons
- Cornstarch – 4 teaspoons
- Instant Clearjel – 4 teaspoons
- Instant tapioca – 2 tablespoons
Blackberries & Red Raspberries
Some berries contain more liquid if they’ve been frozen. Blackberries and raspberries are no exception. They contain a ton of juice and have even more if they’ve been frozen. These two berries need more thickener than apples do.
Amount of Thickener Recommended
- All-purpose flour – 1/2 – 2/3 cup
- Cornstarch – 1/2 cup
- Instant Clearjel – 3/8 cup
- Instant tapioca – 1/2 cup
Blueberries
Blueberries are surprisingly high in natural pectin, which means they require less thickener than their cousins, blackberries and red raspberries. The main exception would be if the blueberries have been frozen, in which case you’ll need more thickener.
Amount of Thickener Recommended
- All-purpose flour – 1/2 cup
- Cornstarch – 6-7 tablespoons
- Instant Clearjel – 1/3 cup
- Instant tapioca – 1/4 cup
Cherries
Cherries are the fruit that throw off most pie bakers. Cherries are naturally juicy so you would think they need a ton of thickener. The assumption is correct but it’s frozen cherries that will throw your pie for a loop. Most cherries are flash frozen. Freezing also converts the moisture on the cherries to tiny ice particles. When the cherries defrost, they have more liquid than when they were fresh.
You will need to increase the amount of thickener listed below if you’re using frozen cherries.
Amount of Thickener Recommended
- All-purpose flour – 1/2 cup
- Cornstarch – 6-7 tablespoons
- Instant Clearjel – 6-7 tablespoons
- Instant tapioca – 3-3 1/2 tablespoons
Peaches
Peaches are juicier than apples but contain less natural pectin. They require more thickener than apples but less than most of the berry pies.
Amount of Thickener Recommended
- All-purpose flour – 3/8 – 1/2 cup flour
- Cornstarch – 3/8 – 1/2 cup flour
- Instant Clearjel – 3/8 – 1/2 cup flour
- Instant tapioca – 1/4 cup
Strawberries
I wasn’t surprised to learn that of the most popular fruits used in pies, strawberries have the highest liquid content. Every summer when I go strawberry picking I eat half of them on the way home. If it’s not juicy, it’s not a good strawberry! Needless to say, strawberry filling requires a lot of thickener.
Amount of Thickener Recommended
- All-purpose flour – 3/4 cup
- Cornstarch – 1/2-3/8 cup
- Instant Clearjel – 3/8-1/2 cup
- Instant tapioca – 3/8-1/2 cup