What's The Absolute Best Thickener For Fruit Pie?

Are you making a fruit pie but are unsure which ingredient to use as the best thickener for its filling? We got to pick an expert's brain so you don't end up with a runny fruit pie. If you're thinking the ingredient is cornstarch, you're close. According to Walleska Cianfanelli, the executive pastry chef at Wilton Sweet Studio, the answer is actually tapioca flour or starch.

"[Tapioca starch] produces a crystal-clear, glossy pie filling that holds its shape," she explains. "Unlike cornstarch, it doesn't dull flavors, and unlike flour, it doesn't create a cloudy filling. Tapioca starch also has great freeze–thaw stability, which makes it ideal for making your pies ahead of time." Additionally, tapioca starch is easily accessible in many supermarkets across the United States and is a gluten-free ingredient. Aside from being a thickening agent, it has many additional uses, especially for bakers. One can make cookies, cakes, boba, and other gluten-free desserts with tapioca starch. 

Knowing which ingredient to use is half the battle, but if you use too much it can mess up the pie's consistency, and too little will leave you with a watery pie. "[The amount] depends on the fruit you will be using," she says, "For juicy fruits (berries, stone fruits) use 1½ to 2 tablespoons of tapioca starch per cup of fruit. For less juicy fruits (apples, pears) use 1 to 1½ tablespoons of tapioca starch per cup of fruit."

Let's say you already have a fruit pie and it's quite runny. This happens, especially when you cook juicy fruits. They simply release more water when cooked. Cianfanelli wants you to not fret; you can still fix a runny fruit pie. "First, make sure you chill it fully," she notes, "many thickeners don't set until the pie is completely cool." You'll notice this with soups and gravies that include thickening agents like cornstarch or tapioca starch. They become thicker and goopy once refrigerated.

"If it's still soupy after chilling, cover the crust edge with foil and return to a [preheated] 350 degree Fahrenheit oven for 15 to 25 minutes to activate the thickener." This should do the trick. Of course, fruit pies can be a little tricky. Our expert adds, "If it's still runny, it means you need more thickener, so call it a rustic crisp and serve it with some ice cream on top!" Aside from ice cream, there are at least 15 unique garnishes for bakery-worthy pies, which you should definitely consider to fix a runny pie.