Swiss Water vs sugarcane EA vs CO₂: which decaf should you buy
Four processes account for essentially every decaf on a European specialty bag. How they actually differ in the cup, which label claims survive contact with the regulation, and why the process matters less than you have been told.
Sources on this page · Directive 2009/32/EC · Swiss Water · Cafe Imports · Descamex · Max Planck Gesellschaft ·
Every decaf starts the same way: caffeine is water-soluble, and green coffee is full of things that are also water-soluble and that you very much want to keep. Every process is a different answer to that one problem — how do you take out the caffeine without taking out the coffee.
Four processes account for essentially everything you will see on a European specialty bag. This page compares them. Each one has its own page with the mechanism, the plants, the numbers and the label claims picked apart: Swiss Water, sugarcane EA, CO₂ and Mountain Water.
The short version
| Solvent | Where | Removal claimed | Leans toward | |
|---|---|---|---|---|
| Swiss Water | None | British Columbia | 99.9% (supplier guarantee) | Origin character, clean, chocolate–caramel |
| Sugarcane EA | Ethyl acetate | Colombia | Minimum 97% | Sweetness, chocolate, faint fruit |
| CO₂ | Carbon dioxide | Germany, Italy, Mexico | 97–99% | Body, lipids, mouthfeel |
| Mountain Water | None | Veracruz | Above 97% (plant’s own claim) | Tobacco, malt, caramel |
Where the marketing breaks down
Two claims do most of the damage.
“Chemical free.” Only Swiss Water and Mountain Water use no extraction solvent, and even for them the phrase is marketing rather than a technical claim — water is a chemical. On a sugarcane EA bag it is simply wrong: ethyl acetate is a solvent, molasses-derived or not, and it sits in Annex I Part I of Directive 2009/32/EC.
“99.9% caffeine free.” This is Swiss Water’s guarantee about Swiss Water’s process. It has escaped onto Mountain Water bags, where the plant itself claims above 97%. If you see 99.9% next to a process that is not Swiss Water, it did not come from the plant.
The related confusion is between a supplier guarantee and the law. The EU threshold for calling something decaf is 0.1% caffeine by dry weight (Directive 1999/4/EC). That is a ceiling on what is left, not a floor on what was removed — two very different claims that imply nothing about each other.
The “natural” question
Sugarcane EA is routinely sold as natural or naturally decaffeinated because the ethyl acetate is fermented from sugarcane molasses. Molasses-derived ethyl acetate is chemically identical to any other ethyl acetate. The sourcing story is true; the implication that nothing solvent-like touches the bean is not.
Worth keeping in proportion: Cafe Imports state a maximum of 10 ppm residual ethyl acetate in the bean, and a ripe banana carries roughly 200 ppm naturally. The objection to the marketing is that it is inaccurate, not that the coffee is dangerous.
So which should you buy
The process is a weaker predictor of cup quality than either the green coffee that went in or the roast that came out. A mediocre lot decaffeinated by Swiss Water is still a mediocre lot. The processes are close enough that origin and roaster competence dominate.
That said, if you are choosing between two otherwise comparable bags:
- You want the origin character to survive — Swiss Water, or CO₂.
- You want maximum sweetness and a chocolate-forward cup — sugarcane EA.
- You want body and mouthfeel for milk drinks or espresso — CO₂.
- You want to avoid solvents entirely on principle — Swiss Water or Mountain Water. Both are water-only.
And one honest caveat on all of that: the trade contradicts itself constantly here. Perfect Daily Grind has quoted cuppers saying you cannot really tell the difference on the table, and elsewhere described EA as having the greatest impact on original taste. Both positions are in print. Nobody has run the study.
The comparison that actually tells you something
Buy the same origin decaffeinated two different ways and taste them side by side on the same day, same water, same grinder. That is the only comparison that tells you anything about your own palate, and it is cheap.
BLACKBIRD in Germany is currently the easiest single place to do it — they carry CO₂, Swiss Water and sugarcane EA lots at the same time.
Questions
- Which decaf process tastes best?
- No published head-to-head sensory comparison exists, so anyone answering confidently is reporting trade consensus rather than evidence. The consensus: Swiss Water and CO₂ preserve origin character best, sugarcane EA gives the sweetest and most chocolate-forward cup, and CO₂ gives the most body. The green coffee and the roast matter more than any of this.
- Which decaf processes use no solvent?
- Swiss Water and Mountain Water. Both are water-only and fall outside the EU extraction-solvent directive entirely. Sugarcane EA uses ethyl acetate and CO₂ uses carbon dioxide; both are regulated as extraction solvents, though CO₂ leaves no residue.
- Is one decaf process healthier than another?
- There is no evidence that any permitted process produces a health difference in the cup. Ethyl acetate is capped at around 10 ppm residual in the bean against roughly 200 ppm occurring naturally in a ripe banana, and CO₂ and the water processes leave no residue at all.
Sources
Regulation · European Parliament and Council, 2009
Does not say It does not certify any process. Swiss Water and Mountain Water fall outside it entirely because they use no extraction solvent — that is an exemption, not an endorsement.
Industry · Swiss Water Decaffeinated Coffee Inc., 2026
Does not say The 99.9% figure is not a certification-body threshold and does not transfer to other water processes. Mountain Water is frequently quoted at 99.9% on the strength of this number; Descamex themselves claim above 97%.
Industry · Cafe Imports, 2023
Does not say Molasses-derived ethyl acetate is chemically identical to any other ethyl acetate. The sugarcane origin is a sourcing fact, not a difference in what touches the bean, and "natural" on this basis is marketing.
Industry · Descamex, 2026
Does not say Descamex do not claim 99.9%. That figure circulates widely on Mountain Water bags and in roaster copy, and it did not come from the plant — it appears to have been borrowed from Swiss Water's separate guarantee.
Industry · Max-Planck-Institut für Kohlenforschung, 1970
Does not say Not all commercial "CO₂ decaf" is supercritical. CR3's process is documented as subcritical liquid CO₂ at around 23 °C and 70–80 bar — a real distinction if you are naming the process on a bag.
The processes in full
Each one has its own page: how it works, where it physically happens, and how the claims on the bag hold up.
Swiss Water Process
A water-only process run at a single plant in British Columbia, using coffee extract already saturated with everything except caffeine. The best known name in decaf, and the most misunderstood — it is a company guarantee, not a certification.
Sugarcane EA
Ethyl acetate fermented from sugarcane molasses, used as an extraction solvent in Colombia. The sweetest-cupping process and the one whose marketing is furthest from its chemistry.
CO₂ process
Caffeine dissolved out under pressure by carbon dioxide above its critical point. The most selective process and the best for body and mouthfeel — and the most expensive to run, which is why you see so little of it.
Mountain Water Process
A water process run in Veracruz using glacier-fed watershed water. Mechanically a close cousin of Swiss Water — and the process most often described with a number its own plant does not claim.