Sanitize the empty 330 ml aluminum can and all equipment with a food-safe sanitizer, then rinse if required by sanitizer instructions. Ensure the can is dry and free of debris.

Make the syrup (concentrate)

In a clean vessel, combine 35 ml high fructose corn syrup (or equivalent sucrose syrup) with 2 ml caramel color, 1 ml phosphoric acid solution, 0.8 ml natural/artificial flavor blend, 50 mg caffeine (if using) and 10 mg sodium benzoate (if using). Stir or gently heat to fully homogenize the syrup ingredients. Do not carbonate the syrup.

Prepare carbonated water

Chill 330 ml carbonated water to 0–4°C. Using a carbonation system, carbonate plain chilled water to approximately 4–4.5 volumes CO2 (this yields a typical soda fizz). If you have pre-carbonated water, keep it under pressure and cold to retain carbonation.

Blend syrup and carbonated water

Measure 330 ml carbonated water into a clean, chilled pressurized mixing vessel or soda dispenser. Slowly add the prepared syrup (about 39.8 ml total volume including flavor/color/acid components) into the carbonated water while gently stirring with a sanitized spoon or using a low-shear recirculation to avoid excessive CO2 loss. The final fill volume should be roughly 330 ml in the can; account for headspace when filling.

Fill and seal the can

Quickly transfer the blended soda into the sanitized 330 ml aluminum can, leaving approximately 8–10 mm headspace for pressure. Immediately seam the can using a can seamer rated for carbonated beverages. Ensure the seam is tight and leak-free.

Carbonation adjustment and leak test

If additional CO2 is needed, place the sealed can in a pressurized carbonator or in a cold environment and force-carbonate for a short time at controlled pressure per equipment instructions. Check the can for leaks by submerging in lukewarm water and looking for escaping bubbles. Dry the can after inspection.

Chill and condition

Chill the sealed can at 0–4°C for at least 24 hours to allow flavors to marry and carbonation to stabilize. Store upright in a cool place until ready to distribute or consume.

Serve

Open the can carefully (tilt to reduce foaming if very cold). Pour into a chilled glass if desired and enjoy. Discard if the can is swollen, leaks, or smells off.

Equipment & packaging

Ensure all equipment (mixing vessel, seamer, carbonation system) is clean and food-safe. Follow manufacturer instructions for CO2 handling, can seaming, and pressurized systems. Use personal protective equipment as required. Dispose of or recycle packaging responsibly.