Good, dead-ripe fruit is sweet enough that it doesn’t require lots of extra sugar when making desserts. But sugar plays a larger role than just sweetening in making sorbet–it also affects texture and freezability. Too little sugar will produce a sorbet that freezes rock hard when stored, and will be full of ice crystals even when fresh. Here are some strategies for reducing sugar without compromising quality.
Instead of adding simple syrup to your fruit puree, try stirring sugar directly in (superfine sugar dissolves best). The taste will be cleanest, and you won’t be adding unnecessary water, which could help produce ice crystals. A pinch of salt helps bring out the fruit’s flavor.
Add a bit of alcohol (about 2 T of vodka for a neutral taste, or use a liqueur with a complementary flavor) toward the end of your ice cream machine’s freezing cycle. Alcohol inhibits overfreezing.
Remember that if your mixture has the perfect sweetness before freezing, it will be less sweet after, as freezing mutes sweetness. So adjust accordingly!