CO₂ decaf is coffee that has had its caffeine removed using pressurised carbon dioxide and water, before roasting. Under high pressure, CO₂ behaves partly like a gas and partly like a liquid. In that state it picks up caffeine but leaves most of the compounds that make coffee taste like coffee. No chemical solvents touch the beans, which is why CO₂ decaf is known for tasting close to the real thing.
How the CO₂ process works
- Soak: green (unroasted) beans are soaked in water, so they swell and the caffeine can move.
- Pressurise: the beans go into a sealed steel vessel, and CO₂ is pumped in at very high pressure.
- Extract: the CO₂ flows through the beans and draws out the caffeine.
- Separate: the caffeine is taken out of the CO₂, which is then reused.
- Dry: the beans are dried back to normal. They're then shipped to roasters like us.
How it compares with other decaf methods
| Method | What removes the caffeine | Notes |
|---|---|---|
| CO₂ | Pressurised carbon dioxide and water | No solvents; keeps flavour well |
| Swiss Water® / Mountain Water | Water and carbon filters | No solvents; flavour can be slightly softer |
| Ethyl acetate ("sugarcane") | A natural solvent made from fermented sugar | Often adds a fruity sweetness |
| Methylene chloride | A chemical solvent | Cheap and common in supermarket decaf; residues are tightly regulated |
Is decaf completely caffeine-free?
Not completely. Decaffeination removes almost all of the caffeine, but a cup of decaf still has a few milligrams. A normal cup of coffee has somewhere around 60–120mg. If you need to avoid caffeine entirely for medical reasons, ask your GP.
Our decaf: Zibby
Zibby is a 100% arabica from Central and South America, decaffeinated by the CO₂ method. We roast it to a medium roast in St Austell. It tastes of creamy milk chocolate, caramel and soft nuts, and most people can't tell it's decaf. It works as espresso, in a cafetière or as filter coffee, and it comes whole bean or ground.
Quick answers
Is CO₂ decaf chemical-free?
Yes. It uses only carbon dioxide and water, with no chemical solvents.
Does decaf taste worse?
Older, cheaper decaf often did. Good green coffee decaffeinated by CO₂ and roasted fresh tastes like normal coffee.
Can I drink decaf in the evening?
That's what most people buy it for. Decaf is a good way to have an after-dinner coffee without losing sleep.
