Decaf begins as ordinary green coffee, which is processed before roasting to remove the vast majority of its caffeine, typically 97% or more, while leaving the rest of the bean's flavour compounds largely intact. It can be made from any origin or roast style, so a good decaf is defined less by being decaffeinated and more by good beans and careful roasting, exactly like any other coffee.

Several decaffeination methods exist. The Swiss Water Process uses only water, temperature and time, without chemical solvents, to draw caffeine out of green beans. Solvent-based methods use a solvent (commonly ethyl acetate, often derived from fruit, or methylene chloride) to selectively remove caffeine from beans that have been steamed or soaked. The CO2 method uses pressurised carbon dioxide as the extracting agent. All are done before roasting.

Decaffeination methods differ mainly in how much of the bean's other flavour compounds they preserve alongside the caffeine; the Swiss Water and CO2 methods are generally considered gentler on flavour than older solvent-based approaches, though all modern methods have improved considerably.

Wherever coffee's flavour and ritual are wanted without the stimulant, an evening espresso after dinner, a second or third cup later in the day, or simply as a everyday choice for anyone sensitive to caffeine.