Most coffee drinkers who have heard of chemical-free decaf know “Swiss Water.” The brand is decades old, the marketing has been consistent, and water-process decaffeination is associated almost entirely with the Swiss Water trademark in the public mind.
There is a second water-process method that produces equivalent quality and gets a fraction of the attention. Mountain Water Process, run by Descamex out of Veracruz, Mexico, has been operating since 1984 and processes a meaningful share of the world’s water-decaffeinated coffee. For drinkers who care about chemical-free decaf, Mountain Water deserves the same recognition Swiss Water has earned.
This is what Mountain Water Process is, how it compares to Swiss Water, and why both exist as separate operations.
How Mountain Water Process works
The basic principle is identical to Swiss Water: caffeine is removed from green coffee using water, time, and an osmotic gradient. No solvents are involved.
The specific Descamex method:
Step one: green coffee beans are soaked in water to expand them and make their internal structures permeable.
Step two: the beans are immersed in a flavor-saturated water solution that has been pre-loaded with all of coffee’s water-soluble compounds except caffeine. Because the solution is already saturated with the flavor compounds, only caffeine moves from the beans into the water. The flavor compounds stay in the beans.
Step three: the now-caffeinated water is passed through activated carbon filters that capture the caffeine. The filtered water, still flavor-saturated, is recirculated to remove caffeine from the next batch of beans.
Step four: the decaffeinated beans are dried back to standard moisture levels and shipped.
The result: green coffee that has had 99.9% of its caffeine removed but retains the flavor compound profile of its original state. The beans can then be roasted normally and brewed normally.
The Mountain Water method differs from Swiss Water in one significant variable: the water source. Descamex sources water from glacial springs at the base of the Pico de Orizaba volcano, the highest peak in Mexico. The water profile is described as soft, mineral-balanced, and unusually pure. Swiss Water uses water from coastal British Columbia. Both produce excellent results; the source water itself is part of each operation’s identity.
How Mountain Water and Swiss Water compare
The two processes are functionally equivalent for most purposes. The differences:
One: location. Swiss Water is in British Columbia, Canada. Mountain Water is in Veracruz, Mexico. The proximity matters for green coffee logistics. Coffee from Latin American origins (Brazil, Colombia, Costa Rica, Guatemala, Mexico itself) can ship to Mountain Water more cheaply and quickly than to Swiss Water. Coffee from East Africa or Indonesia ships more efficiently to Swiss Water.
Two: certification. Swiss Water has more aggressive certification marketing. The Swiss Water Decaffeinated Coffee Inc. trademark appears on bags and websites. Mountain Water has historically been more of a B2B operation, processing coffee on behalf of roasters without a strong consumer-facing brand. This is changing slowly as Mountain Water-processed decafs start appearing on retail shelves with the method called out.
Three: bag claims. A bag of decaf that says “Swiss Water Process” was processed at the Swiss Water facility in BC. A bag that says “Mountain Water Process” or “MWP” was processed at the Descamex facility in Veracruz. Both are accurate, specific claims. A bag that just says “water processed” could be either, or could be a smaller water-process operation. The specific method on the bag is the trust signal.
Four: residual caffeine. Both methods can achieve 99.9% caffeine removal, though specific certification thresholds vary. Swiss Water certifies to 99.9%. Mountain Water typically certifies to 99.9% though some lots are sold at 99.8%. For practical purposes, both are within the range that has no meaningful impact on caffeine-sensitive drinkers.
Five: capacity and scale. Swiss Water has expanded significantly over the past decade and now processes a large share of the global premium decaf supply. Mountain Water is smaller but has been growing. Both have enough capacity that specialty roasters can source from either.
The net: for most coffee drinkers, the choice between Swiss Water and Mountain Water is more about which roaster you trust and what specific green coffee is available than about any meaningful quality difference between the two processes.
Why Mountain Water exists separately from Swiss Water
A common assumption is that one method is older and the other is newer, or that they share parent ownership. Neither is true.
Descamex (Mountain Water) began operations in 1984. Swiss Water in its current form began operations in 1988 (though the underlying patent on water-process decaffeination dates to the early 1980s). The two operations developed independently, leveraging different equipment and different source water, but applying the same fundamental principle.
The reason both still exist: green coffee logistics. Decaffeinated coffee is a single-step processing operation that requires the green coffee to physically travel to the decaf plant. Producing decaf coffee in Mexico from Brazilian green is meaningfully cheaper and faster than producing decaf coffee in Canada from Brazilian green. For a specialty roaster sourcing single-origin Latin American coffees, Mountain Water is often the natural choice. For a roaster sourcing across continents, Swiss Water’s scale and capacity can be the better fit.
Some roasters use both. The choice is operational, not philosophical.
What it means for the cup
For most drinkers, the cup tastes the same. Both methods preserve the green coffee’s flavor compound profile, and a well-roasted decaf from either origin can score 85+ on the SCA cupping scale.
If anyone could blind-taste a difference between Swiss Water and Mountain Water versions of the same green coffee, it would be the very small number of professional cuppers who do this kind of side-by-side regularly. For general coffee drinkers, the differences are below the threshold of perception.
What matters more than which specific water-process plant did the decaffeination:
- The starting green coffee. Specialty-grade green produces specialty-grade decaf regardless of which water method ran. Commodity green produces commodity decaf.
- The roast profile. A specialty water-process bean roasted poorly is still a bad cup. A well-roasted profile makes the difference.
- Freshness. Both Swiss Water and Mountain Water decaffeinated coffees lose their volatiles at the same rate as caffeinated coffee. Roast date stamps matter.
These three variables drive the cup quality much more than the specific water-process plant used.
Where Heist sources
Our coffee is water-processed. We have used both Swiss Water and Mountain Water depending on the green coffee origin and the specific lot. The decision per lot is made by our green coffee partners and the decaf processor with the right capacity at the right moment.
What is constant: no chemical solvents touch any Heist coffee. Both Swiss Water Process and Mountain Water Process meet that standard. The specific facility name on the bag changes with the lot; the standard does not.
Smooth Talker is our everyday water-process decaf. Blueprint is the rotating single-origin. Both use specialty-grade green coffee processed with either Swiss Water or Mountain Water depending on lot.
The honest framing
For most consumers, “water-processed decaf” is a sufficient quality signal. The specific facility name (Swiss Water vs Mountain Water) adds traceability without changing the cup quality meaningfully.
For coffee enthusiasts who want to know exactly where their decaf was processed, the bag claim matters. Roasters who use Mountain Water are usually proud of the source and call it out. Roasters who use Swiss Water do the same.
The pattern to watch: a bag of decaf that says “water processed” generically without naming the facility is using the language to signal premium-ness without committing to a specific operation. This is not always a red flag, but the more specific the claim, the more verifiable the supply chain.
Mountain Water Process is real, it is excellent, and it deserves more recognition than it gets. If you have been drinking Swiss Water decaf and have never tried a Mountain Water decaf, the experience will be familiar; if you have been told “water processed” by a roaster who would not specify which, ask which one.
Frequently Asked Questions
What is Mountain Water Process decaf? Mountain Water Process is a chemical-free decaffeination method developed by Descamex in Veracruz, Mexico. It uses water from glacial springs at Pico de Orizaba to remove 99.9% of caffeine from green coffee while preserving the bean’s flavor profile. No chemical solvents are involved.
Is Mountain Water Process the same as Swiss Water Process? The two methods are functionally equivalent. Both use water as the only solvent, both achieve 99.9% caffeine removal, and both preserve flavor compounds. They differ in location (Mexico vs Canada), water source, and which green coffee origins ship most efficiently to each facility.
Is Mountain Water Process decaf healthy? Yes. Mountain Water Process uses no chemical solvents at any stage. The only inputs are water and the green coffee itself. Residual caffeine is 99.9% removed, leaving 1 to 3 mg per cup, well below thresholds for sleep or cardiac effects.
Why don’t more brands market Mountain Water Process? Mountain Water Process has historically operated more as a B2B service for roasters than as a consumer-facing brand. Swiss Water has invested more in trademark marketing. Both are real, equivalent water-process methods; the difference is brand visibility rather than process quality.
Where can I buy Mountain Water Process coffee? Look for bags that explicitly say “Mountain Water Process” or “MWP” on the packaging. Many specialty roasters use Mountain Water for their Latin American single-origin decafs because of geographic proximity to the green coffee source. The claim should be specific to the facility, not just “water processed.”
What to read next
- The Science Behind Decaf Methods. The chemistry of how different decaffeination processes work.
- What Low Acid Coffee Actually Means. How origin and processing affect coffee acidity.
- Why Most Decaf Tastes Bad (And How We Fixed It). The category context for premium water-process decaf.
No Curfews is the editorial dispatch from Heist, a coffee company that thinks the second half of the day deserves better. We publish lab results, sources, and the occasional opinion. Join the list if this is the kind of thing you want in your inbox.