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What to do if sweet potato pie is runny?

Why is my sweet potato pie runny?

There are a few common reasons why sweet potato pie can turn out runny:

  • Overmixing the filling – Too much stirring can cause the starch in the sweet potatoes to break down too much, resulting in a loose texture.
  • Undercooking – Sweet potato pie filling needs sufficient time in the oven to set up. Underbaking will lead to a runny pie.
  • Too much liquid – Adding too much milk, cream, or eggs to the filling can make it excessively thin.
  • Incorrect thickener – Sweet potato pie filling should be thickened with cornstarch or flour. Using the wrong amount can make the filling too thin.
  • Watery sweet potatoes – Older or waterlogged sweet potatoes have higher moisture content and can lead to a looser pie.
  • High humidity – On very humid days, the excess moisture in the air can prevent the pie from setting up properly as it bakes.

So in summary, overmixing, underbaking, too much liquid, insufficient thickener, old sweet potatoes, and high humidity are the most common culprits for a runny sweet potato pie. Let’s look at each of these issues in more detail.

Overmixing the Filling

It’s important not to overmix the sweet potato filling once you’ve added the eggs and evaporated milk. Too much stirring can cause the starch molecules from the potatoes to break down too much, resulting in a filling that is thin and loose rather than thick and firm.

Aim to mix just until the ingredients are blended – no more than about 1 minute of stirring once the wet ingredients go in. Overbeating the filling is one of the most preventable reasons for a runny pie.

Underbaking the Pie

Sweet potato pie filling needs adequate time in the oven for the eggs to set and the starch to fully gelatinize. Underbaking is another very common reason for a runny pie.

Be sure to bake the pie for the full time recommended in your recipe, at least 45-60 minutes. And check that your oven is reaching the proper baking temperature. Use an oven thermometer to verify the temperature if needed.

The center of the pie should be set but still gently jiggly when fully baked. If the center seems excessively loose and wet still, continue baking for another 10-15 minutes until set.

Too Much Liquid

The proper ratio of sweet potatoes to liquid is important for thickening the filling enough. If you add too much milk, cream, or eggs, the filling can become too loose.

Follow your recipe carefully for the correct amounts of liquid ingredients. Most recipes call for around 1 cup of evaporated milk and 3 eggs. Too much more than that can result in issues.

You can sometimes compensate by adding a bit more cornstarch or flour to absorb the excess moisture if your filling is too thin. But best is to measure the liquids accurately.

Incorrect Thickener

Sweet potato pie filling should be thickened either with cornstarch or flour. Using the proper type and amount is key.

Typically 2-4 tablespoons of cornstarch or flour is used for a standard 9-inch pie. Too little thickener can lead to a runny pie.

Conversely, adding too much thickener can make the filling gluey and gummy. Follow your recipe for the right amount to use.

Substituting arrowroot starch for regular cornstarch can also lead to a filling that is too loose, since arrowroot does not gelatinize as firmly.

Old or Watery Sweet Potatoes

For best results, use fresh sweet potatoes that are firm and not shriveled. Older sweet potatoes or ones that have sat in water too long tend to have higher moisture content.

When you cook down the potatoes, this extra moisture content gets concentrated into the filling, resulting in a looser texture.

Be sure to drain any excess water from the sweet potatoes after boiling or roasting them. Let them air dry for 15-20 minutes after mashing to allow even more moisture to evaporate.

You can also compensate by adding a bit more thickener if your potatoes seem very moist and watery.

High Humidity

On very rainy or humid days, the excess moisture in the air can impact the pie as it bakes. The moisture in the air can prevent the filling from firming up properly and setting into a sliceable texture.

If it’s a very humid day, you may need to bake the pie longer to fully evaporate the moisture and set the filling. An additional 10-15 minutes can help drive off enough moisture for the pie to set up better.

Letting the baked pie cool fully before slicing also allows more time for the filling to firm up. Though humidity can make it tricky, a little extra baking time can often compensate.

How to Fix a Runny Sweet Potato Pie

If your sweet potato pie still turns out runny, there are a few tricks you can try to fix it:

  • Chill it thoroughly – Refrigerate the pie for at least 4 hours or overnight. This allows the filling to gel and firm up.
  • Rebake it – Try baking the runny pie for an additional 10-15 minutes at 375°F to help set the filling.
  • Add a binder – Mix 1 tablespoon cornstarch with 1 tablespoon water and stir into the runny filling to thicken.
  • Top with whipped cream – Soft peaks of whipped cream help camouflage a loose filling.
  • Serve it warm – The filling will be looser when warm anyway, so serve warm with ice cream on top.

Chilling is often the easiest solution for salvaging a runny pie after baking. The filling will continue to set up as it cools. Refrigerating overnight allows the starch molecules to recrystallize and turn firm.

If chilling alone doesn’t do the trick, rebaking with a touch more cornstarch stirred in can help absorb excess moisture and bind the filling. Topping with billows of whipped cream or ice cream also disguises a filling that didn’t quite set.

While not ideal, a runny pie can still taste perfectly delicious. Just getting the filling thoroughly chilled makes a big improvement in texture.

How to Prevent a Runny Sweet Potato Pie

To avoid a runny sweet potato pie in the first place:

  • Don’t overmix once liquids are added
  • Bake at 375°F for 45-60 minutes until just set
  • Measure liquids accurately based on recipe
  • Use 2-4 Tbsp cornstarch or flour as thickener
  • Use firm, not old sweet potatoes; drain well
  • Bake longer if it’s an extremely humid day

Following basic precautions when mixing, baking, and measuring ingredients per the recipe will go a long way towards preventing issues.

Let’s look closer at some key tips:

Don’t Overmix the Filling

As mentioned earlier, resist the urge to beat the filling excessively once the eggs and liquid are added. Just until incorporated, no more than about 1 minute.

Bake at 375°F for 45-60 Minutes

The baking time and temperature in your recipe is critical to ensure the filling sets up. Check for doneness at the minimum time, but be prepared to bake longer especially if your oven runs cool.

Measure Liquids Accurately

Too much evaporated milk or eggs will throw off the thickening power of the starch and can result in a filling that just refuses to gel no matter how long you bake it. Stick closely to the recipe amounts.

Use the Proper Thickener

Cornstarch or flour at about 2-4 tablespoons per pie is the proper thickener to bind the filling. Too little and the filling will be loose. Too much can make it gummy.

Use Fresh, Firm Sweet Potatoes

Old, shriveled sweet potatoes have much more moisture content. Be sure to start with firm, smooth sweet potatoes and drain them well after cooking.

Bake Longer on Humid Days

When the humidity is very high, you need to bake for longer to properly dry out and set the filling. An extra 10-15 minutes should do the trick.

Tips for Making the Perfect Sweet Potato Pie

Follow these top tips for sweet potato pie success:

  • Cook sweet potatoes until very soft – This maximizes starch gelatinization for a thick filling.
  • Blend cooked potatoes while still hot – Hot potatoes puree smoother.
  • Don’t overbeat once eggs and liquid are added.
  • Chill filling at least 2 hours before baking – This allows starches to hydrate.
  • Grease pie plate well – Sweet potatoes can stick.
  • Make decorative crust edges – Visually camouflages any filling irregularities.
  • Use a pie shield if edges brown too quickly.
  • Check for doneness at minimum baking time.
  • Cool pie thoroughly before slicing – At least 4 hours.

Taking these extra steps will help you achieve sweet potato pie perfection every time!

How to Store and Serve Leftover Sweet Potato Pie

Leftover pie should be stored properly for the best flavor and texture:

  • Refrigerate pie loosely covered with plastic wrap or foil. Do not use an airtight lid.
  • Sweet potato pie will keep for 3-4 days refrigerated.
  • Let refrigerated pie come to room temperature before serving, about 2 hours.
  • Reheat leftover slices gently before serving by warming in a 250°F oven for 10 minutes.
  • Freeze pie up to 2-3 months for longer storage. Thaw overnight in fridge before serving.
  • Drizzle slices of warm pie with caramel sauce for added decadence.

Properly stored, leftover sweet potato pie can be just as delicious as the original! The key is keeping the pie loosely covered in the fridge so the filling stays smooth and sliceable. Letting the pie come to room temperature before serving also improves the texture. Gently warming leftovers and topping with ice cream or caramel sauce can transform them into a fabulous dessert.

Troubleshooting Common Sweet Potato Pie Problems

Issue Potential Cause Solution
Runny filling Underbaked; too much liquid; old potatoes; high humidity Chill thoroughly; re-bake; add cornstarch slurry
Cracked surface Oven too hot; filling not chilled before baking Bake at 375°F; chill filling 2+ hours first
Burned edges Foil not covering crust edges; oven hot spots Cover crust rim with foil strips; rotate pie mid-bake
Dense or gummy filling Overbaked; too much thickener Be careful not to overbake; use amount of cornstarch/flour specified in recipe
Bland flavor Not enough spices and seasoning Double check quantity of sugar, spices, vanilla, etc. per recipe

This chart summarizes the most common sweet potato pie issues, their likely causes, and how to fix them. With a combination of proper ingredients, accurate mixing, sufficient baking time, and a well-calibrated oven, you can master making stellar sweet potato pie.

Ingredient Substitutions for Sweet Potato Pie

In a pinch, you can modify sweet potato pie with some simple ingredient swaps:

  • Sweet Potatoes – Substitute pumpkin puree or butternut squash
  • Eggs – Swap in egg substitute like Ener-G per package directions
  • Evaporated milk – Use half and half or heavy cream
  • Spices – Omit cinnamon and nutmeg, use ginger and cloves only
  • Sugar – Replace up to half the sugar with pure maple syrup
  • Pecans – Substitute walnuts or omit nuts entirely

Swapping in similar starchy vegetables like pumpkin or butternut squash can work well as a substitute for sweet potatoes. Just adjust seasoning to complement the different squash flavor.

Heavy cream or half and half can stand in for evaporated milk. And the pie will still taste great with only cinnamon or only nutmeg if you don’t have both spices on hand.

Get creative with ingredient tweaks to adapt pie to what you have available! The keys are maintaining the basic ratio of potatoes to liquid and using a proper thickener.

Recipe for Easy Sweet Potato Pie

This simple recipe yields classic sweet potato pie with just a handful of ingredients:

Easy Sweet Potato Pie


  • 2 cups mashed, cooked sweet potatoes
  • 2/3 cup evaporated milk
  • 2 eggs
  • 3/4 cup sugar
  • 1/4 cup butter, melted
  • 1 tsp cinnamon
  • 1/2 tsp nutmeg
  • 1/2 tsp ginger
  • 1 tsp vanilla
  • 2 tbsp cornstarch
  • 1 unbaked 9-inch pie crust


  1. Preheat oven to 375°F. Combine potatoes, milk, eggs, sugar, butter, and spices in a large bowl. Mix until thoroughly blended. Do not overbeat.
  2. Stir in cornstarch and vanilla until just incorporated.
  3. Pour filling into unbaked pie crust. Use foil strips to cover exposed crust edges to prevent over-browning.
  4. Bake for 45-60 minutes or until center is nearly set. Let pie cool fully before slicing, at least 4 hours.
  5. Serve with whipped cream or vanilla ice cream if desired. Refrigerate leftovers.

This easy sweet potato pie has a smooth, silky filling with classic fall spice flavors. The key is not to overmix once the eggs are added. Letting the pie chill for several hours allows the filling to fully set before serving. Enjoy this simple homemade pie on your holiday table or for Sunday dinner any time of year!


A runny sweet potato pie can be frustrating, but is often salvageable. Chilling thoroughly and rebaking are good ways to help firm up the filling if your pie turns out too loose. Beating the ingredients too much, underbaking, and high humidity are common culprits for ruining the texture. Following key tips for mixing, baking, and ingredient selection will help prevent issues. Store leftovers properly covered in the fridge and gently reheat slices before serving. With the right techniques and recipes, you can master baking sweet potato pie with a smooth, nicely set filling every time. Let me know if you have any other sweet potato pie questions!