The piped choux pastry expands in the oven as the water and fat liquids are converted into steam the egg and flour proteins set and the choux goods should be baked well, if not the inside if the choux products will be moist and soften the case when cool resulting in a collapsed product that will not keep very long.
With most items never open the oven before 20 minutes has passed, except for very small items such as swan heads or petit profiteroles for soup garnish.
Pre-baked choux eclairs and choux buns can be purchased that have a 6 month shelf life and are used extensively in the bakery and catering industry
