What is decaf coffee?

Decaf coffee is coffee from which at least 97 % of the caffeine has been removed from the green beans before roasting, according to the European standard. The process relies on a solvent — water, supercritical CO2, sugarcane-based ethyl acetate, or dichloromethane — that selectively pulls out the caffeine while leaving as much of the coffee aroma intact as possible.

EU regulation (Directive 1999/4/EC, now folded into the CE Regulation) caps the residual caffeine of decaf coffee at 0.1 % of the weight of roasted whole beans and 0.3 % of dry soluble extract. In practice an Arabica bean holds around 1.2-1.5 % caffeine and a Robusta 2.2-2.7 %; after compliant decaffeination the concentration usually drops below 0.1 %, which translates to roughly 2 to 5 mg of caffeine in an espresso cup, versus 60 to 80 mg for a regular espresso.

The decaf market has been reinventing itself. For decades it was cornered into medical or late-night use and openly considered dull in the cup; since around 2015-2020 it has become a playground for specialty roasters. Three processes dominate today. Swiss Water Process, developed in Switzerland in the 1930s and industrialised in Canada since the 1980s, uses only water saturated with coffee compounds (Green Coffee Extract) to pull caffeine out by osmotic gradient — no chemical solvent, often paired with organic certification. Supercritical CO2, pioneered at Max Planck in Germany in the 1970s, brings CO2 to 70-100 bar and 40-60 °C into a state between liquid and gas that selectively extracts caffeine. Natural sugarcane ethyl acetate (sugarcane EA) is produced from fermented cane molasses, mainly in Colombia; it is often marketed as 'naturally decaffeinated' since the molecule occurs in many fruits.

A fourth route, called the 'Euro process' or 'direct contact', uses dichloromethane (DCM) or synthetic ethyl acetate. It remains the cheapest and still supplies a large share of commodity decaf in Europe. Flavour-wise, decaffeination always strips away some of the volatile aromatics — a specialty-grade decaf typically shows a slightly lighter body and a rounder acidity than its caffeinated counterpart. In Belgium, where morning filter is still widespread, decaf holds a steady foothold in Brussels, Ghent and Liège roasters, often served late in the day or to drinkers sensitive to caffeine.

Decaffeination processes, at a glance