A proper Italian gelato di crema is sort of like vanilla ice cream, only in place of vanilla, you infuse the milk with a modest grating or shaving of lemon zest. This doesn't turn it into lemon ice cream, itself a cool dollop of heaven. What happens, rather, is that the small-volume scent of lemon makes the eggs eggier and the custard creamier. (Photo: Meredith Heuer for The New York Times)
