Fall French 75 Recipe

Name: Fall French 75 Recipe
Ingredients: For the Concord Grape Puree:; 1 1/2 cups Concord grapes, stems removed (about 8 ounces with stems); 1/4 teaspoon juice from 1 lemon; For the Cocktail:; 1 ounce London dry gin, such as Beefeater; 1/2 ounce St. Germain elderflower liqueur; 1/2 ounce Concord grape puree; 1/4 ounce juice from 1 lime; 1/4 ounce simple syrup (see note); 2 ounces chilled sparkling wine, or more to taste