β Caster Sugar (Best Vegan Option)
1:1 by volume (1 tablespoon caster sugar per 1 tablespoon powdered sugar)Caster sugar has finer granules than regular granulated sugar, allowing it to dissolve rapidly in the cream mixture used for panna cotta. This rapid dissolution is critical to maintain the smooth, creamy texture characteristic of panna cotta.
To ensure success, whisk the caster sugar thoroughly into the warm cream base until fully dissolved before adding gelatin. Avoid adding sugar to cold cream as it may not dissolve completely.
Compared to powdered sugar, caster sugar may impart a slightly less velvety mouthfeel but will not significantly alter the flavor or setting properties, making it the closest practical substitute.