In a clean small bowl or measuring cup, combine the sucrose (11 g) and glucose/dextrose (11 g) with 2 tablespoons (30 ml) of hot water to dissolve. Stir until fully dissolved to create a simple sugar solution. Add the citric acid (0.25 tsp), sodium bicarbonate (a pinch, 0.125 tsp), and sodium citrate if using (0.125 tsp). Stir until evenly distributed. This creates the acidic/salty balance typical of commercial energy drinks.

Add active ingredients

Allow the sugar solution to cool to room temperature. Add the taurine (1000 mg), D-glucuronolactone (250 mg, if using), niacin (8 mg), pantothenic acid (2 mg), pyridoxine (0.5 mg), and B12 (0.01 mg). If using powdered caffeine, dissolve an amount that provides 80 mg of caffeine in a small amount of water (be precise — caffeine is potent). Alternatively, use a prepared caffeine solution that supplies 80 mg. Stir thoroughly until powders are fully dissolved. Add the natural/artificial flavor (0.25 tsp) and the preservative (potassium sorbate) if using.

Combine with carbonated water

Place 8 oz (about 240 ml) of chilled carbonated water in a tall glass or pitcher. Gently pour the prepared concentrate into the carbonated water while stirring slowly with a spoon to integrate without causing excessive foaming or loss of carbonation. Taste and adjust: if too sweet, add a splash more carbonated water; if too tart, add a pinch more sugar solution.

Chill and serve

Add ice if desired. Serve immediately in a chilled glass. Store any leftover mixture (un-carbonated concentrate) refrigerated in a sealed container and combine with fresh carbonated water when ready to serve. Consume responsibly and do not exceed recommended daily caffeine and stimulant intake.