Choux pastry (the kind used in eclairs and creampuffs) is very picky, and depends heavily on the chemical properties of eggs. Five years ago I played around with trying to make it eggless with aquafaba and xanthan gum. It didn't work, but now that we have vegan egg white protein, can we do this for real?

Nope. I gave it several tries over vacation, and wasn't able to get it to puff properly. Here's the closest I got:

• Panade
  • 1/2 C water
  • 1/4 C milk
  • 5T butter
  • 1t sugar
  • 14T flour
• Egg replacement
  • 9T water
  • 1/2t powdered lecithin
  • 3T plus 1t egg white powder
  • 2T butter, melted but cool

As with standard choux I heated the water, milk, butter, and sugar to a boil, then added the flour. I mixed it well, let it cool a little, and then gradually added the egg (replacement) while beating will in between additions. The batter looked just right:

But when I baked it, it didn't inflate. I tried again, and this time took advantage of the AirBnB's nice oven to observe that there were little bubbles on the skin. Video:

youtube

My hypothesis for why this isn't working is that eggs normally have a range of proteins that set at different temperatures. The most common (~54%) is ovalbumin which sets at 176–183F, and this is what the precision-fermented egg white is made out of. But there's also ovotransferrin (~12%) which sets at 142–149F, and I'm guessing this early setting is why choux made from normal eggs forms a thin flexible crust in time to capture steam and inflate. Whereas in my version the steam just leaks it out.

Models think I should try either potato protein isolate (149F) or methylcellulose (gels at 140F, reverses on cooling). Thoughts?