Dilmah uses a solvent-free decaffeination process called "Carbon Dioxide Method". The decaffeination process uses Carbon Dioxide (CO₂) - a naturally occurring gas that, when combined with the tea at high pressure, reaches a supercritical state. This allows small molecules to attract small caffeine molecules and extract them while leaving larger flavour molecules intact.

This process is considered as the safest and most eco-friendly as it retains greater levels of flavour and health-giving antioxidants.