Swiss Water Process
Decaffeination method without chemical solvents, using water charged with coffee compounds (GCE, Green Coffee Extract). Removes 99.9% of caffeine while preserving more aromatic compounds than chemical methods.
Background & Context
Swiss Water Process (SWP) is a commercial chemical-free decaffeination method developed in Switzerland in 1933 and now operated commercially by Swiss Water Decaffeinated Coffee Company in Burnaby, British Columbia, Canada. The process uses water saturated with green coffee solids (Green Coffee Extract, or GCE) and activated charcoal to selectively extract caffeine without using chemical solvents. Green coffee is soaked in GCE — water that contains all coffee solids except caffeine — creating a diffusion gradient where caffeine (but not other flavour compounds) migrates from the beans into the GCE. The caffeine-laden GCE is then filtered through activated charcoal to remove caffeine, and the process is repeated until 99.9% of caffeine has been removed. Swiss Water claims 99.9% caffeine removal vs. 97% for solvent methods.
Practical Use
Swiss Water Process decaffeination has become the specialty coffee standard for chemical-free decaf, certified organic-compatible and certified by the Swiss Water brand. For specialty roasters, the key quality consideration is the GCE's osmotic extraction: because the GCE is pre-saturated with all other coffee solids, only caffeine migrates out — preserving the vast majority of the flavour compounds that make specialty coffee distinctive. In practice, SWP decaf is noticeably cleaner than solvent decaf (methylene chloride, ethyl acetate methods) and roasts more predictably due to the consistent moisture content post-treatment. For consumers, SWP decaf still contains approximately 2–5mg caffeine per double espresso shot — meaningful for highly caffeine-sensitive individuals. Swiss Water certification appears on bag labels as the green SWP logo. For roasters communicating Swiss Water decaf to specialty consumers, the clearest claims are: "chemical-free decaffeination", "99.9% caffeine removed", and "flavour compound preserved". Avoid overclaiming that SWP decaf is indistinguishable from regular coffee — even the most careful SWP treatment removes some flavour volatiles alongside caffeine. The best SWP decafs are light-to-medium roasted specialty-grade green coffees from Ethiopia, Colombia, or Kenya — the initial quality ceiling determines the decaf ceiling. A commodity-grade green coffee going through SWP will not become a specialty decaf; it will remain commodity quality with removed caffeine.
Related Terms
Related terms: Caffeine, Caffeine metabolism, Organic certification, Specialty coffee.