Diet Coke Recipe

Chill and prepare carbonated water

Ensure carbonated water is well chilled (ideally 35-40°F / 2-4°C). Use freshly opened bottled or keg carbonated water to retain maximum carbonation.

Measure 12 fl oz (about 355 ml) of chilled carbonated water into a clean 12–16 fl oz serving glass or chilled soda bottle, leaving a little headspace at the top.

Add 1 tsp caramel color or caramel syrup to the carbonated water. Stir gently once or twice to disperse — avoid vigorous stirring to minimize CO2 loss.

Add 0.25 tsp of 5% citric acid solution and 0.25 tsp of 1% phosphoric acid solution to balance acidity. Stir gently once to combine.

Add 0.0625 tsp aspartame (very small amount) plus 0.015 tsp acesulfame K. If using liquid sweetener concentrates, add dropwise and taste cautiously. These quantities approximate the sweetness level of a diet cola for one 12 fl oz serving.

Add 0.25 tsp cola flavor concentrate or homemade cola extract. If using a concentrated cola syrup intended for larger batch use, reduce the amount accordingly; start small and adjust to taste.

If desired, add 0.05 tsp food-grade caffeine solution for an authentic bite. Caffeine is optional — omit if you prefer caffeine-free. Stir very gently to incorporate flavors while preserving carbonation.

Add 1 drop of natural citrus oil (orange or lime) if you want a subtle citrus top note. Do not overdo citrus oils — they are potent.

Taste carefully by pouring a small sip into a spoon or tasting glass. Adjust sweetener by adding tiny increments (a pinch or tiny 0.01–0.02 tsp steps) if needed; adjust cola concentrate or acids in similarly small increments. Stir gently after each adjustment.

If serving over ice, add 4–6 ice cubes to the serving glass before pouring in the soda mixture, or pour the mixed soda over ice. Use cold glassware to minimize foam and CO2 loss.

Garnish with a lemon or lime wedge on the rim if desired. Serve immediately to enjoy maximum carbonation.