Diet Dr. Pepper Recipe

Make the concentrated syrup

Combine 1 cup water and 2 cups erythritol (or preferred sugar substitute) in a small saucepan. Heat gently over medium-low, stirring until the sweetener dissolves and the mixture comes to a light simmer. Do not boil vigorously — you only need to dissolve and slightly reduce so the syrup is concentrated (about 4–6 minutes).

Remove the pan from heat. Stir in 1 tsp vanilla extract, 1 tsp almond extract, 1 tsp brown sugar extract (or 1 tsp molasses), and 1 tsp rum extract. Mix thoroughly so aromatic extracts are evenly distributed.

Add 1 tbsp black cherry concentrate and 1 tsp cola extract. Stir until fully combined. If using tamarind paste (1 tsp), whisk it in now to add fruity tang. Add 1 tsp citric acid to introduce the bright cola-like tang and stir to dissolve.

If you want the drink caffeinated, very carefully add a micro amount of caffeine powder (approx. 0.05 tsp). Only use pre-measured food-grade caffeine and handle with extreme care; skip entirely if uncertain. Stir to dissolve.

Taste the syrup and adjust: increase black cherry concentrate or a drop more almond extract for stronger cherry/marzipan notes; add a pinch more citric acid for brightness. Let the syrup cool to room temperature, then transfer to a clean bottle or jar. The syrup will keep refrigerated for up to 2 weeks.

Fill a tall glass with 1 cup of ice cubes (about 8–10 oz by volume).

Pour 2 fl oz (about 1/4 cup) of the prepared flavor syrup into the glass. This gives a concentrated Diet Dr Pepper–style flavor; adjust to taste between 1–3 fl oz depending on sweetness and intensity desired.

Slowly add 12 fl oz chilled carbonated water to the glass to preserve fizz. Pour down the side of the glass or over the back of a spoon for gentler mixing.

Stir gently with a long spoon once to combine syrup and carbonated water. Avoid vigorous stirring which will flatten the carbonation.

Garnish with a fresh lime wedge on the rim if desired. Serve immediately chilled.