Yes. Decaf coffee contains a small amount of caffeine, typically around 7mg in a 200ml UK mug, compared with roughly 100mg for a regular coffee. The decaffeination process removes 97 to 99.9% of the original caffeine, but a trace fraction always survives. UK and EU law only allow a roasted coffee to carry the “decaffeinated” label if the residual caffeine sits at no more than 0.1% by dry weight; for instant coffee, the ceiling is 0.3%.
That is the headline number. The rest of this guide is the detail: what the figure actually looks like by process, what UK regulation requires, what it means if you’re sensitive to caffeine for any reason, and which UK decafs sit at the genuinely low end of the spectrum.
How much caffeine is in a cup of decaf?
About 7mg per 200ml mug at the most-cited UK figure, with the realistic spread sitting between 2mg and 15mg depending on bean origin, decaffeination method, and how the cup was brewed. Set against a regular coffee at ~100mg, that’s around 93% less caffeine, the figure the British Heart Foundation uses.
| Drink (200ml UK mug) | Typical caffeine |
|---|---|
| Decaf coffee | ~7mg |
| Decaf tea | ~2mg |
| Green tea | ~30mg |
| Regular tea | ~50mg |
| Espresso decaf (single shot) | 3 to 15mg |
| Espresso (single shot) | 60 to 80mg |
| Regular coffee | ~100mg |
The peer-reviewed evidence base is thinner than you might assume. The most-cited primary study (McCusker, Journal of Analytical Toxicology, 2006) measured 0 to 13.9mg per 16oz brewed serving across 10 US outlets, and 3.0 to 15.8mg per espresso decaf shot at one chain. Variance is real. The number printed on the bag is rarely the number that lands in your cup.
Why decaf isn’t caffeine-free
No commercial decaffeination process is 100% efficient, and none of them try to be. Caffeine sits inside the bean’s cellular structure alongside the flavour compounds that make coffee worth drinking. The solvent (water, CO2, ethyl acetate or methylene chloride) strips most of the caffeine out, but the final fraction binds at a molecular level that can’t be touched without damaging the aromatics in the same place.
That trade-off is unavoidable. Push for 100% extraction and you destroy the cup; stop at 99.9% and you get a coffee that still has a measurable trace, but tastes like coffee. Every commercial decaffeinator settles in roughly the same range: 97% removal at the floor, 99.9% at the ceiling.
Caffeine by decaffeination method
There are four mainstream commercial methods, and the residual caffeine differs less than the marketing pages suggest. What differs more is the residual chemistry (whether any solvent residue is left behind), and whether the process happens at origin or in a Northern Hemisphere plant.
| Method | Caffeine removed | Residual per 200ml mug | Solvent residue |
|---|---|---|---|
| Swiss Water | 99.9% | 1 to 3mg | None |
| CO2 (supercritical) | 97 to 99% | 2 to 5mg | None (CO2 vents to atmosphere) |
| Sugar cane / EA | 97 to 99% | 2 to 5mg | Naturally-derived solvent (EA), <10ppm |
| Methylene chloride | 97 to 99% | 2 to 7mg | Synthetic solvent (MC), <2ppm under UK/EU law |
Swiss Water
99.9% caffeine removal, certified against the EU dry-weight standard. On a typical green bean carrying around 1.2% native caffeine, that puts the residual in the cup at 1 to 3mg per 200ml mug. The process uses only water, temperature and activated carbon, and no organic solvents touch the beans. It’s the cleanest pick for anyone genuinely caffeine-sensitive, because both the caffeine numbers and the chemical residue numbers are at the floor. We currently list 25 Swiss Water coffees in the directory, mostly from South American origins.
Sugar cane / ethyl acetate (EA)
97 to 99% caffeine removal, with most published residuals landing at 2 to 5mg per 200ml mug. The “sugar cane” name describes the source of the solvent (fermented sugar cane molasses, mostly produced at Descafecol in Colombia) rather than the active mechanism, which is still solvent extraction. EA is the solvent. The processing happens at origin in Colombia, which keeps more of the value with the producer country. We list 53 sugar cane decafs.
CO2 (supercritical)
97 to 99% caffeine removal. Supercritical CO2 (above 31°C and 73 atm) acts as a selective solvent that bonds with caffeine while leaving the flavour compounds intact. The CO2 then depressurises, the caffeine drops out, and the gas is reused. Solvent residue: none, because the CO2 returns to the atmosphere. Expect 2 to 5mg of residual caffeine per 200ml cup. The method is capital-intensive, so the plants are mostly large industrial operations and the coffees command a premium.
Methylene chloride (MC)
97% removal at the regulatory floor. Residue limits are set at 10ppm by the FDA and 2ppm by the EU and UK, so the European bar is five times stricter than the US. Measured residue in GMP-compliant plants typically lands at 0.3 to 1mg per kg of green coffee, well below the legal ceiling. Caffeine in the cup is similar to the other methods: 2 to 7mg per 200ml mug. The reputational issue is the solvent itself; methylene chloride is classified as a probable carcinogen by the IARC, NTP, EPA and WHO, and a coalition led by the Environmental Defense Fund (with the Center for Environmental Health as a co-petitioner) petitioned the FDA to ban it in coffee in 2024. The EU and UK currently permit it. It’s common in commodity blends and supermarket instant decaf, and rare on UK specialty shelves.
If you want a decaf where the chemistry is as clean as the caffeine numbers, Swiss Water or CO2. If you want one where the producing country keeps more of the value, sugar cane EA. If methylene chloride doesn’t bother you, fine, but it’s worth knowing it’s there.
The UK labelling rule (0.1% / 0.3%)
UK law sets two caffeine ceilings depending on what kind of decaf you’re buying. They are easy to confuse.
For roasted coffee, the EU standard most UK producers and brokers operate to is 0.1% caffeine by dry weight. That’s the figure circulating in producer literature, contract specifications, and broker disclosures, derived from the broader EU coffee framework rather than a single UK statute.
For instant coffee and coffee extracts (the Nescafé Gold Decaf shelf, broadly), the UK statutory rule is more explicit. The Coffee Extracts and Chicory Extracts (England) Regulations 2000 (SI 2000/3323, implementing EU Directive 1999/4/EC) allows the “decaffeinated” descriptor only on extracts where “the residual anhydrous caffeine content does not exceed 0.30 per cent of its coffee-based dry matter content”. Equivalent SIs cover Scotland, Wales and Northern Ireland.
In practical terms: a typical green bean carries 1 to 2% caffeine by weight. The 0.1% ceiling means at least 90 to 95% of caffeine must be removed for a roasted coffee to wear the label. The 0.3% instant ceiling means at least 70 to 85% removal. Most reputable processes clear both with daylight to spare. Enforcement sits with Trading Standards under the Food Safety Act 1990; the bar is low enough that non-compliance is rare in UK specialty.
How much decaf is “too much”?
For most people, more than you’ll ever drink.
The NHS limit in pregnancy is 200mg of caffeine per day (Tommy’s and NHS England both restate this). At 7mg per mug, that’s 28 mugs of decaf to hit the cap. A couple of mugs a day is well inside guidance, and the NHS pregnancy infographic explicitly recommends switching to decaf in preference to regular coffee. If you’re pregnant and worried, the answer is to check with your midwife rather than ration mugs.
For the general adult population, the EFSA upper safe limit is 400mg of caffeine per day, with no more than 200mg in a single dose. Reaching 400mg on decaf would take around 57 mugs. Functionally unreachable.
For sleep, caffeine has a half-life of around five hours in healthy adults, longer if you carry CYP1A2 variants that slow your metabolism. A 7mg decaf at 8pm leaves you with 3.5mg at 1am, a dose low enough that most drinkers won’t notice it, though sensitive individuals can still respond to small amounts close to bedtime.
For anxiety, palpitations or atrial fibrillation, individual thresholds vary widely. Decaf’s 7mg sits at the very low end and isn’t where the published literature focuses. The British Heart Foundation’s position on AFib is that moderate caffeine, equivalent to 4 to 5 cups of coffee a day, doesn’t lead to abnormal heart rhythms, while noting that some people are more sensitive than others. Cardiologists routinely permit decaf for stable AFib patients.
The honest version: if you’re genuinely caffeine-sensitive, a Swiss Water decaf in the 1 to 2mg range is the cleanest cup you can buy. If you’re not, the difference between processes is small enough that you can pick on flavour, not on numbers.
The lowest-caffeine decafs on the UK market
A short list of UK decafs that sit at the floor of the residual-caffeine range:
- Apostle Coffee, The Needle’s Eye Organic Decaf (Sumatra, Swiss Water, £15.55). Butterscotch, marjoram and nutmeg. The only Sumatran Swiss Water on the directory; genuinely interesting flavour notes that break the Swiss Water comfort-chocolate baseline.
- Artisan Roast, Decaf Brazil Swiss Water (Brazil, Swiss Water, £9.50). Almond, molasses, cocoa. The archetypal Brazilian Swiss Water at a sensible price band. A good entry point for anyone moving up from supermarket decaf.
- Insurgence Coffee, Retreat Decaf (Brazil, Swiss Water, £7.50). Dark chocolate and nut. The cheapest specialty Swiss Water currently catalogued.
- Bad Hand Coffee, Decaf (Colombia, Swiss Water, £14.00). Chocolate, apple, toffee. Bournemouth roastery, well-regarded in UK specialty circles.
All four are Swiss Water, which sets the realistic caffeine floor at 1 to 3mg per 200ml mug. If you’re choosing on caffeine alone, that’s the bracket to stay in. If you want to compare across origins or methods, the Swiss Water filter and the sugar cane filter are the quickest routes through the catalogue.
Stock churns. Specialty roasters bring in a single Swiss Water lot, sell through it, then move on, so the directory is the live source rather than this list.
Browse the catalogue
We’ve catalogued 116 UK decafs across the four processes, with current prices, tasting notes and live stock status. Filter by decaffeination method to see the spread, or sort by lowest published caffeine to find the bottom of the range.