Pepsi's Mountain Dew is a popular citrus-flavored soda with a secret recipe that gives it its refreshing taste. The exact ingredients and proportions used in Mountain Dew are known only to a select few at Pepsi. It is believed to contain a blend of citrus flavors, including orange and lemon, along with a hint of caffeine. Mountain Dew has become a favorite among soda enthusiasts, known for its bold and energizing flavor.