Flat Choux Pastry: Why It Happens and How to Fix It (With a Tested Recipe)

Flat choux pastry is one of the most common baking problems. Instead of rising into tall, hollow puffs, the dough spreads in the oven or collapses as soon as it cools. Fortunately, the cause is almost always the dough’s moisture, the oven temperature or opening the door too early.

Below, you will find each cause with its fix. After that, there is a tested choux recipe for cream puffs, profiteroles and éclairs.

Why Choux Pastry Turns Flat: The Quick Answer

• The dough had too much egg, so it was too wet to hold its shape.
• The flour paste was undercooked, so it could not absorb enough egg.
• The oven was too cool, so there was not enough steam to puff the dough.
• You opened the oven early, or took the puffs out before they were dry.

Flat Choux Pastry: Causes and Fixes

Too much egg in the dough

Cause: Most of the time, this is because all the eggs went in at once. As a result, the dough became too runny to stand up.

Fix: Add the beaten eggs a little at a time and stop when the dough passes the V-test. In other words, when you lift the spoon, the dough should fall slowly and leave a V-shaped point.

Too little egg in the dough

Cause: Stiff dough cannot stretch, so instead of flat choux pastry you get small puffs that crack on top.

Fix: Keep adding egg until the dough is smooth and glossy. Also, eggs vary in size, so always judge by texture instead of the exact number.

An undercooked flour paste

Cause: The paste needs cooking to dry out and bind. Otherwise, it holds less egg and less steam.

Fix: Stir the paste over medium heat for 2–3 minutes, until a thin film forms on the bottom of the pan. Then cool it for 5 minutes before adding the eggs.

The wrong oven temperature

Cause: Choux rises only from steam, because it has no baking powder. Therefore, a cool oven cannot make enough steam.

Fix: Start at 200°C (400°F) for 15 minutes, then lower it to 180°C (350°F) to dry the shells. In addition, check your oven with a thermometer.

Flat choux pastry after baking

Cause: The shells were still wet inside when they came out, so they sank as the steam cooled.

Fix: Bake until deep golden and firm. Then pierce each shell and return it to the switched-off oven for 10 minutes, so the inside dries.

Tested Choux Pastry Recipe

Choux pastry ingredients

• 120 ml (½ cup) water
• 120 ml (½ cup) whole milk
• 110 g (½ cup) unsalted butter, cubed
• 1 teaspoon sugar
• ½ teaspoon salt
• 140 g (1 cup + 2 tablespoons) all-purpose flour, sifted
• 4–5 eggs, beaten

How to make the choux pastry

1. Boil the liquids. First, heat the oven to 200°C (400°F). Bring the water, milk, butter, sugar and salt to a full boil.
2. Add the flour. Next, take the pan off the heat and stir in all the flour at once until a smooth ball forms.
3. Dry the paste. Then return the pan to medium heat and stir for 2–3 minutes, until a film forms on the bottom.
4. Cool. After that, move the paste to a bowl and beat it for 1 minute to release steam.
5. Add the eggs. Beat in the eggs a little at a time until the dough is glossy and passes the V-test.
6. Pipe. Pipe 4 cm (1½-inch) mounds onto a lined tray, and smooth any peaks with a wet finger.
7. Bake. Finally, bake for 15 minutes, then lower the heat to 180°C (350°F) and bake 15–20 minutes more without opening the door.

Tips to Avoid Flat Choux Pastry

• Never open the oven during the first 20 minutes, because the cold air stops the rise.
• Use bread flour for extra-strong shells, for example for large éclairs.
• Fill the shells only when they are completely cool; otherwise, they turn soft.

Storage Tips

Keep unfilled shells in an airtight box for 2 days, or freeze them for 1 month. Then crisp them in a hot oven for 5 minutes before filling. For filling ideas, see our fruit tart recipe, which includes a vanilla pastry cream.

Then and Now

Choux pastry has been made in France since at least the 1700s, and the name means “cabbage” because the puffs look like small cabbages. Later, pastry chefs used it for éclairs, profiteroles and the tall croquembouche. You can read more about choux pastry on Wikipedia.

Flat Choux Pastry FAQ

Can I fix choux dough that is too runny?

Not easily. Instead, make a small extra batch of paste without eggs and beat it into the runny dough.

Why are my choux hollow but soft?

They were underbaked, which also leads to flat choux pastry later. Therefore, bake them longer and dry them in the oven after piercing.

Can I make the dough ahead?

Yes. Keep the piped, unbaked mounds in the freezer, and bake them straight from frozen with 5 extra minutes.

For more baking fixes, read our guides to croissant butter leaks and why soufflés fall.

Hungry for more? If you found this guide to flat choux pastry useful, our digital cookbook has 31 more recipes like this one, ready to print or read on your phone.