Primary Causes

• Cream puffs deflate when the conditions are not right when they are being created. The crusty pastries must have the appropriate ratio of beaten eggs, flour, butter and water to create a paste. Add too much water and the cream puff flattens. Baking them in an oven that is too hot, or not hot enough, also makes the finished cream puff to go flat. Another cause of flat cream puffs is undercooking -- taking them out of the oven too soon.

The Importance of Heat

• To combat the heat problem, keep your oven at 325 degrees Fahrenheit. An oven that is too hot will brown the cream puff on the outside before the inside has built the proper structure needed to stand up as a puff. The result is a fallen cream puff. Maintaining constant heat is another issue. The heat inside the oven must be hot and constant to produce steam. The paste must steam until the cream puff rises and sets. Opening the oven too often or tinkering with the temperature controls during baking will lead to a soggy, flat cream puff.

The Importance of Steam

• The steam from cooking cream puffs helps them rise, but only if the steam is allowed to escape. As this occurs, the cream puff expands. Once the steam is gone, the interior bakes into a flaky structure strong enough to hold up the pastry. Issues with steam can lead to flat cream puffs. This includes placing the pastries to close together to bake. There must be enough space to let the steam escape. Leaving any excess steam inside after baking is another problem. To prevent it, use a toothpick to poke a small hole into the top of the cream puff.

Remember the Pate a Choux

• Follow your recipe carefully to get the appropriate balance of eggs, water, flour and butter. Together, these ingredients make up the pate a choux, which is the basis for eclairs, profiteroles and, of course, cream puffs. No matter what you are making, the pate a choux must result in the same type of finished pastry. It must be brown, bard and flaky on the outside. Anything less will be improperly cooked and probably flat.