The Derby Fizz is a classic cocktail that originated in the Southern United States during the 19th century. It's a refreshing and effervescent drink that's perfect for sipping on a hot summer day, and is a popular choice at the Kentucky Derby. The combination of gin, lemon juice, simple syrup, and orange bitters creates a tart and citrusy flavor, with the club soda adding a refreshing fizz. The cocktail is traditionally served in a Collins glass, garnished with a lemon twist. Whether you're enjoying a lazy Sunday brunch or celebrating at a summer party, a Derby Fizz is a classic cocktail that's sure to impress.