Use the Swiss Water Process
Use the direct solvent process
Use the indirect solvent process
Use supercritical carbon dioxide extraction
Start with green coffee beans
Soak the beans in hot water to dissolve caffeine
Separate caffeine from the water using charcoal filters or solvents
Re-soak the beans in the caffeine-free water to restore flavor compounds
Dry the beans after decaffeination
Roast the decaffeinated beans normally