Sour Cream (Best Option)
1/4 cup per 1/4 cup Greek yogurtSour cream has a similar fat content and acidity level as Greek yogurt, which helps replicate the tangy flavor and thick consistency essential for the custard batter in French toast. The acidity also aids in tenderizing the bread and balancing the sweetness.
When substituting, use a 1:1 ratio to maintain batter consistency. Stir sour cream well before measuring to ensure even texture. Avoid thinning it with water, as this will reduce the batter's ability to coat the bread effectively.
The final French toast will have a slightly richer flavor with a comparable creamy texture, preserving the traditional custardy mouthfeel that Greek yogurt provides.