Dear The Practical Kitchen,
Every time I make a pie or a tart, the dough seems to bubble up in the oven. The bubbles often go away, but sometimes they crack the dough and cause leaks, and other times they push the filling out of the way causing spillage. How do I stop my pie crust bubbling???
Bubble, Bubble, Toil, and Trouble
Oh, I wish I knew what kind of pie you're making so I could tailor this better. Some pies you bake with the filling inside from the start, and others require pre-baking (also called parbaking or blind baking) before you add the filling and finish baking (or let set in the fridge, depending on your filling).
What causes pie crusts to bubble? Bubbling pie dough is caused by steam getting trapped under or inside the dough during baking and having nowhere to go. The steam comes from the butter in the dough, which turns to liquid and then to steam in the oven.
The steam is a good thing, and is the reason why you want to keep your pie dough well chilled and avoid handling it too much before baking — in the oven, those chilled pieces of butter turning to steam is what creates your nice flaky layers.
That steam less of a good thing if you're making a sweet shortcrust pastry or crust that should have a cookie-like texture (like the one in my pear and gruyere tart recipe). In that case you really want to avoid bubbles of any sort!
In either case, when that steam comes from air trapped beneath the crust and has nowhere to go it pushes the crust up creating bubbles and cracks. Steam is good. Bubbles are bad.
So let's talk about how to press out air bubbles, how to use docking and pie weights to prevent pie crust bubbling, and how to seal your pie crust to prevent a soggy bottom.
📋 What you'll need
- Pie weights - To weigh the crust down during baking.
- Parchment paper or aluminum foil - To shield the crust and so you can remove the pie weights during the baking process.
- A fork - For docking.
- Pastry brush - Natural bristle, not silicone for more even coverage
- Egg white - Lightly beaten to seal the crust.
🥧 How to press out air bubbles
When you first transfer your pie crust into the pie dish, air is likely to get trapped below the dough.
The overhang crust tends to want to pull the crust outward as it settles in. You need to release that tension so the crust can settle down into the pie dish.
Go all the way around the crust lifting it up to let any trapped air out, then smooth it back down so no air is trapped. Use the backs of your fingers on the other hand to press the crust into the corners.
Why use the back of your fingers? It's a smoother edge and you're less likely to accidentally pierce or scratch the crust with your nails.
Even the most diligently smoothed out crust can still have air trapped beneath it or inside the dough causing it to bubble. So you've also got to give that air a designated escape route — a process known as "docking."
Read more: "Do I need to grease and flour my pie dish?"
🍴 How to dock your pie dough
If you're pre-baking your pie or tart crust, it's crucial that you dock your pie crust to prevent your pie crust from bubbling.
Docking essentially means using a fork to poke holes all over the dough, making sure to get the sides/walls of the pie dough, too.
These holes allow steam to escape during baking, so it doesn't get trapped under the dough and send your pie crust bubbling. If you're already docking and still having issues with bubbling, you may not be docking enough OR you may not be properly weighing your crust down during baking.
Really make sure you're pressing the fork to the bottom of the pan, and when you think you have enough holes, add a few more. Especially get them near (but not in) the corners of the crust, where the dough is more likely to have air trapped below it.
In pastry school we were taught to use as few docking marks as possible. The reason for this is because the more holes you put in the pie crust, the more room the filling has to seep through them later, creating a soggy bottom.
But if you're not someone who makes pie crusts all the time or if you don't feel very confident in your ability to fit the crust into the pan without trapping air, I do recommend over-docking rather than under.
Tip: Chill the pie crust in the fridge or freezer after docking but before adding the pie weights. The crust will start warming up as you work with it, and you want it to be fairly firm before you add the pie weights so they don't sink into it.
You don't need to dock your pie crust or use pie weights if you're baking the pie dough with the filling already inside. The weight of the filling acts like pie weights and will keep the pie crust in place.
🥧 How to use pie weights
If you're pre-baking your crust, you should use pie weights in addition to docking your crust to keep the dough down.
What are pie weights? Oven-safe weights used to hold the dough in place while it bakes. In a pie crust that bakes with the filling inside, the filling serves as the pie weight. For pre-baked crusts that bake without any filling, pie weights prevent them from bubbling up in the oven.
Flaky deep dish crusts vs shallow shortcrusts for tart pans
- To use pie weights with a flaky pie crust: Crinkle a piece of parchment paper up into a ball, then un-wrinkle it. Crinkling it first makes it much more flexible so it sits nicely inside your pie dish. Make sure you have plenty of overhang so you can grab the corners later to remove them from the pan. Press it down gently into the pie dish over the crust and pour your pie weights into the center. You want the weights to fill the pan at least ⅔ of the way up the sides.
- To use pie weights with a shortcrust or sweet tart crust: Spray a sheet of aluminum foil on one side with non-stick spray, and press it, greased-side down into the tart crust. Press it into the corners and edges of the crust too — you don't want the foil to cut through the crust, but you do want it to hold the walls in place. Then add the weights. Again, you want them to come at least ⅔ of the way up the sides of the pan.
Once your pie or tart dough has baked most of the way through but is still quite pale, you'll remove the pie weights and give it another minute or two of baking to take on some color. You might see it start to bubble at this point, but that's okay — you can deflate those bubbles when you take it out of the oven.
If you're using a no-bake filling, you'll finish baking the crust completely. If you're using a baked filling, you'll want to avoid letting it get too dark or else it'll burn when you bake the filling.
How to remove pie weights: Take your pie all the way out of the oven and put it on a counter or cooling rack. Then grab the edges of the paper (it won't be hot) or use oven mitts to grab the edges of the foil. Lift it off the crust. Then pop the crust back into the oven.
TIP: Do not try to remove the pie weights while the pie is still on the oven rack. If you do this and drop your pie weights you will be extremely sad. Remove them to a bowl on the counter and the worst they'll do is roll around a bit.
🍚 What to use as pie weights
If you're buying pie weights, they come as loose ceramic beads or as a long, stainless-steel chain. But there are also plenty of good DIY options!
- Loose ceramic pie weight beads - This is my preferred type of pie weight. They're often sold too small packages with not enough beads for a whole pie, so make sure you look for a pack with at least 2 pounds of beads. In these photos I'm using a 2.4 pound bag of ceramic pie weights by Jefferson Street Ceramic.
- Long stainless steel pie weight chain - This type of pie weight is most useful in smaller pie crusts, like mini cheesecakes or mini deep dish pies. I don't love it for bigger pies as it doesn't distribute weight evenly across the bottom of the pie and it doesn't apply any weighted pressure up the sides of the pie.
- Dried rice - You can still cook with it after using it as pie weights. Just don't add the rice back to your rice container if any butter or grease got on it during baking.
- Dried beans - You can still cook the beans after using them as pie weights. No waste ftw!
- Granulated sugar - This tip comes from Stella Parks at Serious Eats! Use the same batch of granulated sugar over and over again and you'll notice it takes on a toasty caramelized flavor in the oven. It can be used just like regular sugar in baking in the future as long as it didn't get any butter or grease on it.
Which one you use is really up to you! You may even find your preferences change over time or as you find a method of pie making that works best for you.
I used to prefer the pie weight chain because I didn't have to worry about the beads spilling everywhere when I removed them. But you just can't get the same kind of coverage with the chain as you can with the beads, particularly when it comes to holding the sides of the pie crust in place as it bakes. The chain just isn't big enough.
💭 Sealing your pie and tart crusts
Once you remove the pie or tart crust from the oven, brush it immediately with lightly beaten egg whites to seal all the holes from where you docked it. The egg white should set pretty much immediately on contact because the surface of the pie is hotter than the temperature at which eggs cook.
If it doesn't set and dry immediately, just pop the pie crust back in the oven for 20-30 seconds. Repeat until the surface of the pie is smooth and shiny and the docking holes are entirely sealed. This will prevent the dreaded "soggy bottom" and give you a nice crisp crust.
Between the docking and the pie weights, your crust will be sure to stay down. And if, despite your best efforts, it bubbles up anyway in those last few minutes, that's okay — as soon as it comes out of the oven, gently poke the bubble with a knife or fork to release the steam. Then seal it up with egg whites, and no one will be the wiser.
A final tip, if all else fails: Place your pie or tart pan on a sheet tray while you bake. That way if the you do experience any pie crust bubbling or the crust pushes any pie weights out of the dish, they don't go spilling into the bottom of your oven.
How to Blind Bake a Pie Crust with Pie Weights
- 1 pie or tart crust
- 1 egg white
- Roll your pie or tart crust out on a lightly floured surface.
- Treat the pan with non-stick spray or butter according to recipe instructions. (Not all pie crusts and pans require greasing).
- Transfer the rolled out pie dough to the pie pan, draping the excess loosely over the edges.
- Gently work your way around the crust lifting the crust edges to release any trapped air. Use the backs of your fingers as you go to smooth and press the dough into the creases and corners of the pan. Once the dough is firmly pressed into the pan, chill it in the fridge for 5-10 minutes, then crease or crimp the edges in whatever style you prefer. Chill again if needed.
- Use a fork to poke small holes all over the surface of the crust, making sure the tines of the fork go all the way through the crust. Return the pie crust to the fridge and chill well.
- Crumple a piece of parchment paper into a ball. Unfurl it and press it loosely into the surface of your pie dish. Make sure there is plenty of overhang for you to grab later.
- Fill the parchment paper lined crust with pie weights up to ⅔ of the way full.
- Place the pie crust on a baking sheet and bake according to recipe instructions.
- To remove pie weights, remove pie from the oven. Grab the corners of the parchment paper and lift straight up out of the dish and into a bowl.Be careful, as sometimes the paper can become trapped in a bit of crust during baking.
- Return pie crust to the oven for 1-2 more minutes (or longer, if needed for a fully baked crust).
- Remove pie crust from oven. Deflate any new bubbles with the tip of a paring knife and immediately brush the surface of the pie with egg wash to seal any holes. If egg white doesn't set immediately, return pie to oven for 20-30 seconds so it sets.
- Let cool. Your pie is now ready to fill.
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This post was originally published on 8/15/2019.