Step 1In a small saucepan, stir the sugar with one-fourth cup water over medium heat until the sugar dissolves. Cool. Combine the cooled simple syrup and lemon juice. Makes 1 cup (8 ounces).
Step 1In a large pitcher filled with ice, add the pisco, Cointreau, grape juice and sweet and sour and stir to combine. Strain the cocktail into 4 old-fashioned glasses filled with ice. Slowly pour three-fourths ounce Pinot over the back of a spoon into each cocktail (the Pinot will float on top and slowly diffuse into the cocktail). Garnish with a lemon slice, and float the grapes on top of the drink (if they are still attached to the stem, you can hang the stem on the rim of the glass).