Mountain Dew Recipe

Prepare simple citrus syrup

Combine 1 cup sugar and 1 cup water in a small saucepan over medium heat. Stir until sugar dissolves and the mixture comes to a gentle simmer. Add the orange zest, lemon zest, and lime zest; simmer gently for 3 minutes to release oils.

Remove saucepan from heat. Stir in 1 teaspoon citric acid and 1 teaspoon vanilla extract until fully dissolved. If using, add 1 drop yellow food coloring and 1 drop orange extract or orange flower water. Let the syrup cool to room temperature (about 20–30 minutes) so oils infuse. Strain the syrup through a fine mesh sieve to remove zest solids and transfer to a clean container. Refrigerate until cold.

If adding caffeine powder: weigh carefully (the recipe lists 50 mg for whole batch). Dissolve the measured caffeine into 1 tablespoon warm syrup, then mix thoroughly into the cooled syrup. Caution: caffeine is potent — do not exceed recommended amounts and keep out of reach of children.

Mix soda and citrus

Chill the carbonated water well. In a large pitcher (about 1.5 L capacity), combine 4 cups cold carbonated water with 2 tablespoons fresh lemon juice, 1 tablespoon fresh lime juice, and 2 tablespoons orange juice. Stir gently to blend — avoid vigorous stirring that will remove carbonation.

Add 1/2 cup (or to taste) of the cooled citrus-sweet syrup to the pitcher. Stir gently and taste. Adjust sweetness/acidity by adding more syrup (for sweeter) or an extra 1/4 teaspoon citric acid dissolved in a teaspoon water (for tarter), adding sparingly and tasting between additions.

For a stronger citrus/bright profile, add an extra 1 teaspoon lemon juice or 1/2 teaspoon lime juice, again tasting as you go. If you want the classic bright yellow-green hue, a single drop of green food coloring can be added in addition to the yellow to achieve desired color — optional.

Fill four tall glasses with ice cubes (about 1/2 cup ice per glass). Pour the carbonated citrus mixture over the ice, dividing evenly.

Garnish each glass with a lime or lemon wedge. Serve immediately to retain carbonation.

Store any leftover citrus syrup in the refrigerator for up to 2 weeks. The mixed soda is best consumed immediately; if stored, keep in a sealed bottle and expect some loss of carbonation within a day.