⭐ Club Soda (Best Vegan Option)
Replace 1/4 cup liquid with 1/4 cup club soda per 1 teaspoon baking powder Quick tip: Adds carbonation for lightness but minimal chemical leavening; best combined with whipped eggs.
Club soda contains dissolved carbon dioxide that can introduce some aeration into the quiche custard, helping to lighten the texture slightly. However, it lacks the sustained chemical leavening action of baking powder.
For best results, combine club soda with well-whisked eggs to trap air and improve rise. Use immediately after mixing to retain carbonation.
This method results in a modestly lighter quiche but may not achieve the same rise or tenderness as baking powder, potentially producing a denser custard.