Rainbow Peach Soup

1 cup fresh or frozen raspberries, thawed
3 cups fresh or frozen peaches, thawed
3 tablespoons lemon juice
1 cup peach nectar
1 cup (8 ounces) plain nonfat yogurt
1/4 cup granulated sugar, optional
1 teaspoon almond extract

Place raspberries in a blender; cover and process until smooth. Strain and discard seeds. Cover and refrigerate pur