How is decaf coffee made, and does it cost more?
How decaf coffee is made
Published 5 November 2026. Catalogue figures checked 6 November 2026.
Caffeine comes out of the bean before it is roasted, while the coffee is still green, and there are only three ways anyone does it: wash it out with water, dissolve it in pressurised carbon dioxide, or dissolve it in a solvent. Everything on a bag of decaf is one of those three wearing a trade name. 605 of the 906 decaf coffees we have collected say which one they used.
Does decaf cost more?
No. The median decaf here is £38.00/kg across 764 priced decaf coffees, against £39.00/kg across all 8,610 priced coffees — about 3% less, which is £1.00 a kilo. Both figures are taken at the cheapest bag each roaster sells. A difference that size is not a reason to choose or avoid decaf.
The middle 80% of priced decaf runs from £25.64 to £50.00 a kilo, so a decaf shelf looks much like any other shelf. What it is not is a cheap corner of the market: the processing is an extra step on top of everything else, and it is paid for somewhere. What speciality coffee should cost sets out the whole distribution and which bag every figure is taken from.
The methods roasters name
Counted over the 605 decaf coffees that state a method. A coffee here states at most one, so these rows sum to that figure rather than double-counting. Medians are per kilo at the cheapest bag each roaster sells, and rows with fewer than twenty priced coffees get a count and no figures.
| Method | Coffees | Roasters | £20.00 to £60.00 per kilo | Median |
|---|---|---|---|---|
| Sugarcane | 279 (246 priced) | 178 | £40.00 | |
| Swiss Water | 176 (143 priced) | 102 | £36.00 | |
| Mountain water | 96 (86 priced) | 63 | £38.00 | |
| CO2 | 32 (29 priced) | 24 | £37.95 | |
| Ethyl acetate | 20 (19 priced) | — | only 19 priced | — |
| Methylene chloride | 2 (1 priced) | — | only 1 priced | — |
The bar is the middle 80% of each row, from the 10th to the 90th percentile; the tick is the median. Rows with fewer than 20 priced coffees show a count but no figures, because a median of a handful of coffees is one roaster’s pricing. A coffee with more than one method is counted under each, so the rows do not sum to the catalogue.
Sugarcane — 279 coffees
The green beans are steamed and then washed with ethyl acetate obtained from fermented sugarcane. Caffeine dissolves into the solvent and leaves with it, and the beans are steamed again to drive the solvent off. It is the method named most often on the bags we have read.
Swiss Water — 176 coffees
Caffeine is drawn out into water, and then taken out of the water with activated carbon so the water can go back to the beans carrying everything except the caffeine. No solvent touches the coffee. It is a trademarked process, which is why the words arrive in capitals on a bag.
Mountain water — 96 coffees
The same principle as the other water-based methods — the caffeine leaves in water and is filtered out of it — and named for the water the plant uses rather than for anything different about the chemistry.
CO2 — 32 coffees
The beans are soaked and then held under carbon dioxide at pressure, which dissolves caffeine and leaves most other compounds where they are. It needs more equipment than any of the others.
Ethyl acetate — 20 coffees
A solvent method. Ethyl acetate occurs naturally in ripening fruit and is also made industrially, and a bag that names only the solvent has not said which of the two it used. Where a roaster says sugarcane, they have.
Methylene chloride — 2 coffees
The oldest industrial solvent method, and the one people mean when they say a coffee was chemically decaffeinated. Almost no roaster here names it.
The counts and medians above are measured from the catalogue. The descriptions of what each method does are written, not measured: we have not watched any of these processes and we hold nothing that tests them.
301 bags that say nothing
301 of the 906 decaf coffees here — 33% — name no method at all. That is the roaster deciding what goes on a label, not a gap in this catalogue. We will not guess from the rest of the page: a coffee whose roaster says nothing is not a solvent decaf, and it is not a water decaf either. Why so many coffees say “not stated” explains how the site keeps the roaster’s silence apart from ours.
Two more things this site cannot tell you about a decaf, so that nobody reads an absence as a verdict. We hold no measurement of how much caffeine is left in any of them, because no roaster publishes one we can read. And we hold no tasting data and publish no scores of any kind, so nothing here ranks one method above another in the cup.
Decaf in stock, cheapest first
In stock, priced, and naming a method, cheapest per kilo first at the cheapest bag each roaster sells — which is the price shown on each row. Ordered by price because that is the only order we can honestly put them in.
Questions
How is decaf coffee made?
Caffeine is washed out of the green bean before it is roasted, by one of three routes: water, pressurised carbon dioxide, or a solvent. 605 of the 906 decaf coffees here name the method on the bag, and between them they name 6: Sugarcane (279), Swiss Water (176), Mountain water (96), CO2 (32), Ethyl acetate (20), Methylene chloride (2). The roasting afterwards is the same as for any other coffee.
Does decaf coffee cost more?
No. The median decaf here is £38.00/kg across 764 priced decaf coffees, against £39.00/kg across all 8,610 priced coffees — about 3% less, which is £1.00 a kilo. Both figures are taken at the cheapest bag each roaster sells. A difference that size is not a reason to choose or avoid decaf.
Which decaffeination method is best?
We cannot tell you, and nor can anything on this site. We hold no tasting data, publish no review or cupping scores, and measure nothing about what a process does to a cup. What the method tells you is what was done to the coffee, which is a different question from how it tastes. The only thing the prices here show is that the methods are not far apart. The lowest median belongs to Swiss Water at £36.00/kg a kilo and the highest to Sugarcane at £40.00/kg, and neither figure says anything about the cup.
Is decaf coffee caffeine-free?
No. Every one of these methods removes most of the caffeine rather than all of it. No roaster in this catalogue publishes a figure for how much is left in a form we can read, so no page here can tell you — and we will not estimate it.
Why do so many decaf bags not say how it was done?
301 of the 906 decaf coffees here say nothing about the method, which is 33% of them. That is the roaster's choice about what to print and not a fault in the coffee, and on this snapshot not one of them is a case of us failing to read a method the roaster did publish.