Half-and-Half (Best Option)
1:1 replacement (1 cup half-and-half per 1 cup whole milk)Half-and-half is a blend of milk and cream, typically containing about 10-12% fat, which is higher than whole milk's 3.5-4%. This fat content enhances the panna cotta's smoothness and helps the gelatin set with a luxurious texture.
For best results, use chilled half-and-half and gently heat it with the gelatin to avoid curdling. Because it is richer, you may notice a slightly more indulgent mouthfeel but the flavor remains balanced.
Compared to whole milk, half-and-half yields a panna cotta that is creamier and silkier without being overly heavy, making it the closest substitute in both texture and taste.