Combine Wine and Peach Schnapps: In a large pitcher, pour the bottle of white wine and add the peach schnapps.
Add Lemon Juice and Simple Syrup: Mix in the fresh lemon juice and simple syrup. Stir well to combine. Adjust the sweetness by adding more or less simple syrup according to your taste.
Add the Fruits: Add the sliced peaches, orange, lemon, and if using, raspberries or strawberries to the pitcher.
Chill: Let the sangria mixture chill in the refrigerator for at least 2 hours, or overnight if possible. This allows the flavors to meld together.