What is Swiss Water decaf?
Swiss Water decaf is coffee decaffeinated with water instead of organic solvents. Green coffee soaks in a caffeine-free extract of green coffee, the caffeine moves out of the beans into the liquid, and carbon filters pull it out of the liquid again. Wikipedia's Decaffeination article says the technique was first developed in Switzerland in 1933 and commercialized by Coffex S.A. in 1980.
How the Swiss Water Process works
Wikipedia describes the process in four steps:
- Green coffee beans are soaked in hot water, and the liquid is run through an activated charcoal filter to remove the caffeine. What is left is green coffee extract: water that carries every water-soluble part of green coffee except caffeine.
- Fresh green beans go into that extract. Because the extract already holds the other soluble parts of the coffee, only the caffeine moves out of the beans into the liquid.
- The extract, now carrying caffeine, passes through activated carbon filters again to strip it out.
- The cycle repeats. Wikipedia says the batch takes 8 to 10 hours to reach its decaf target.
All of this happens to green coffee, before roasting. The roaster then roasts the decaf beans like any others. Wikipedia names the Swiss Water Decaffeinated Coffee Company of Burnaby, British Columbia, as the company that introduced the Swiss Water process in 1988.
Under United States FDA standards, decaf must have at least 97 percent of its caffeine removed; the EU standard is 99.9 percent caffeine-free by mass, per Wikipedia.
What Swiss Water decaf tastes like
Every decaf method aims to take out caffeine and leave the flavor precursors in the green coffee as close to their original state as possible, Wikipedia says. Its description of the Swiss Water process shows how this method tries to do it: because the extract already carries the coffee's other soluble parts, only the caffeine migrates, and the rest stays in the green coffee. From there, the roast level you choose shapes the cup as it would any other coffee.
Swiss Water vs other decaf methods
| Method | What removes the caffeine | What Wikipedia says |
|---|---|---|
| Swiss Water | Water, green coffee extract, carbon filters | Uses no organic solvents; 8 to 10 hour batch |
| Carbon dioxide | Water and CO2 under pressure | Steamed beans in a vessel at 300 atm and 65 °C (149 °F) |
| Solvent | Dichloromethane or ethyl acetate | The solvents used today, after benzene was dropped |
| The first method | Steam, acids or bases, then benzene | Invented by Ludwig Roselius in 1903, patented 1906 |
Two more names show up on Montana bags: Mountain Water Process and sugarcane decaf. Wikipedia's article does not cover either by name, so our glossary index has the short versions.
Swiss Water decaf in Montana
None of the Montana roasters we write up stated that a decaf was made by the Swiss Water Process on the pages we read on September 27, 2026. Here is what they did state:
- Mazevo Coffee, Billings, sells Mellow Creek Swiss Decaf, a medium roast. The name says Swiss; its page did not describe the method.
- Rockford Coffee, Bozeman, sells a Brazil decaf made by the Mountain Water Process.
- RamsHead Coffee Roasters, Shields Valley, sells a Colombia sugarcane decaf.
- Ghost Town, Drum, Hunter Bay, Yellowstone, Philipsburg and Montana Coffee Traders sell decaf without naming the method, and Treeline runs a decaf subscription of its own.
If the method matters to you, ask the roaster. A roaster down the road can tell you where its decaf came from, and buying it keeps a Montana roastery in business. More on why local roasters matter.
How to get decaf from the club
Set the style to Decaf in the plan builder on the home page, or read the decaf subscription page. The method depends on the roaster that roasts your box, so the club does not promise Swiss Water. Every bag is 12 oz, whole bean or ground, $16.99, any roast. First bag free, you pay $7.99 shipping. Then $16.99 a bag.
Related terms and sources
- Decaf, CO2 decaf and half caff
- Green coffee beans, the stage where decaffeination happens
- Single origin coffee and coffee blend
Sources: Wikipedia, Decaffeination; Montana roaster decaf listings from each roaster's own site, read September 27, 2026.