Vegan egg white protein fails to puff choux pastry in new experiments

jefftk revisited a five-year-old challenge: making eggless choux pastry (used in eclairs and cream puffs) with modern vegan ingredients. Using precision-fermented ovalbumin (the main protein in egg whites), lecithin, and a standard flour-butter-water base, he produced a batter that looked identical to traditional choux. But when baked, it refused to puff up. A video from an Airbnb oven showed tiny bubbles on the skin, but no inflation. The failure points to a missing component in the egg replacement.

Normal eggs contain multiple proteins that set at different temperatures: ovotransferrin (~12%) sets at 142–149°F, forming a thin flexible crust early enough to trap steam. The ovalbumin (~54%) sets later at 176–183°F. jefftk's replacement only had ovalbumin, so steam leaked out before the crust could form. He plans to try potato protein isolate (sets at 149°F) or methylcellulose (gels at 140°F, reverses on cooling) to mimic ovotransferrin's early-setting behavior. The experiment highlights how complex even a simple pastry can be for vegan alternatives.