You should be using weight of ingredients. So it is not the number of eggs, but the weight of eggs to flour.
Other keys to successful pate a choux is resting the dough before piping; spraying with cooking oil and dusting with sugar cane sugar powdered sugar after piping; freezing to chill thoroughly before baking; baking on a perforated baking mat.
These are most of the steps in a commerically produced elcair. I just took another eclair class a month or so ago. The one thing I modified here is the actual baking because you won’t bake in a commercial oven.
* Sift flour then measure and set aside
* Place butter, water, milk, salt, and sugar into a saucepan over medium heat
* As soon as the mixture starts to boil remove from heat, add all the flour, and whisk vigorously to form a smooth ball and flour no longer visible. Some chefs prefer a silicone spatula, others prefer a balloon whisk.
* Place the saucepan back on the stovetop and cook the dough for 3-5 min over medium heat mixing constantly. The liquid will evaporate from the dough and a thin skin will form on the bottom of the saucepan
* Transfer the dough to the stand mixer bowl and mix on med low speed speed to cool the dough 130°F - 140°F (use the paddle attachment)
* Reduce mixer speed to low. Slowly adding lightly whisked eggs onto the dough Only add a small amount of egg at a time and let the mixer incorporate the egg before adding in more. This is the emulsification process; it is important that the egg properly beat into the dough.
* The dough is ready when it glossy and slowly falls down from the paddle attachment in a V shape. It should hold it's shape, and not be runny. The exact quantity of egg will depend on the flour protein content and how dry the dough.
* Transfer dough into a pastry bag fitted with Open Star tip like an Ateco # 869
* Rest the dough in the refrigerator for 1-2 hours
* Once the dough is rested, pipe on a perforated baking mat (best) or parchment paper (second choice). Do not use a silicone mat as this will distort the shape of the pate a choux.
* When piping, hold the bag still, do not pipe by moving your hands; instead, hold the bag and your hands and arms still and move your upper body over the baking sheet. This will produce even éclairs and reduce fatigue.
* Pipe the 5” (13 cm) long eclairs (35 grams) spaced of 1.5 cm over a perforated mat.
* After piping, apply a thin layer of cooking spray. With a very fine sieve lightly sift some powdered sugar on the surface of éclairs. A thin layer of icing sugar protects the eclairs from bursting.
* Put the finished éclairs in the freezer until they freeze completely. Éclairs can be stored frozen for up to two weeks. After freezing, just put them into an airtight container to protect them.
* Pre-heat oven to 390°F (no fan)
^
* Lower oven temperature to 340°F (no fan) and bake the eclairs for 40 min.
* After 20 - 30 minutes when eclairs look fully formed and developed, open the oven door just a crack for about 10 seconds to release steam.
* 40 min check for doneness.
- golden color
- nice puffed shape
- does not deflate at room temperature
- the center is not raw (some moisture is okay as it will evaporate in cooling)
* Cool the eclairs on the perforated mat
* Use a Bismark tip to fill
Note: if choux is going to be stored frozen, an trimoline (invert sugar) must be added to the dough to prevent ice crystals forming in dough. Approximately 1% is adequate.
^every home oven is different. You will have to experiment to find the temperature that works best with your oven.
