Pour the wine into a medium saucepan and place over medium heat. Simmer until reduced to 1 cup, about 10 minutes. Remove from the heat, and let cool completely. Transfer to a bowl, cover, and refrigerate until cold, about 1 hour.
Place the blackberries and lemon juice in a food processor and puree until smooth, then pour into a fine-mesh strainer placed over a bowl, pressing on the solids to extract the blackberry puree. Discard the seeds.
Whisk the wine and simple syrup into the blackberry puree, pour the mixture into the container of an ice cream machine, and churn according to the manufacturer’s instructions. Transfer to an airtight container and freeze for at least 2 hours before serving.
Simple syrup, commonly used to sweeten sorbetti, bar drinks, and iced tea, is a mixture of water and sugar that’s simmered until the sugar dissolves. While granulated sugar doesn’t dissolve easily in cold liquids (when you try to stir sugar directly into iced tea, for example), simple syrup makes it easier to create sorbetto because it combines easily with fruit purees and other sorbetto ingredients. It keeps for months in a clean container in the refrigerator, so you can scale up the recipe and have a few batches on hand.
MAKES ABOUT 11⁄3 CUPS
1 cup water
1 cup sugar
In a medium saucepan, combine the water and sugar. Place over medium-high heat and bring to a boil, whisking often to dissolve the sugar. Reduce the heat to medium-low and simmer for 4 minutes, while continuing to whisk until all the sugar is dissolved. Remove from the heat and let cool, then transfer to a bowl or container, cover, and refrigerate until cold, at least 1 hour.