In a large bowl, mash the raspberries with a fork. Stir in the wine. Cover and set aside at room temperature for 2 days.
Pass the berries through a fine strainer into a medium saucepan, pressing to extract as much liquid as possible. Add the sugar and simmer over moderate heat until thick and syrupy, about 15 minutes. Pour the syrup into a heatproof bowl and cool to room temperature. Stir in the brandy. Pour the liqueur into clean jars or bottles and refrigerate for up to 2 months.