i live in italy. at our cooking class today, we made this. here is the recipe:
400 ml water
200 g sugar
150 ml fresh lemon juice
1. make syrup. boil water and sugar, with a few strips of lemon skin (no whites) then stir continiously for about 20 min; let cool completely to room temp; remove lemon skins
2. squeeze lemons (do this at the moment you plan to mix with syrup); fliter lemon juice through sieve; mix with sugar syrup.
3. cover and freeze; serve in champagne glasses with curl of lemon peel, and mint leaf; or in hollowed-out lemons that have been frozen
Sgroppino is made with lemon sorbet which has no dairy product (unlike the American style sherbert). The ingredients that I use are: 1 part lemon sorbet, 2 parts prosecco and 1/4 part grappa (vodka is more traditional). I just put the ingredients in a chilled bowl and quickly beat it with a whisk. Also, I like to garnish each serving with a small sprig of rosemary. Some versions have much more sorbet to prosecco which makes it much more like a dessert.
Sorbetto is simply sherbet. The drink-like dessert or dessert-like drink is a sgroppino. Google the name; there are many different recipes out there, but the main ingredients are generally lemon sherbet, prosecco and vodka. A Roman friend made his with only lemon sherbet and vodka,