[jpp]

The gold standard for this in sensory analysis is a triangle test — which I happen to have done with coffee from Ninth St Espresso, who sells a regular and substantial identical decaf. We brewed 3 identical batches (where 2 were the same beans and the 3rd was the other bean). In an office with ~12 tasters, the ability to pick out the “different” beans was 33%… ie random chance.

If the above sounds confusing, consider red wine vs white wine… visual inspection alone would get you 100% accuracy.

I used to believe decaf processing would have to change the taste, but empirically, with admittedly untrained tasters (but ones who know coffee very well), we couldn’t tell.

[reillys]

Decaf is simple to pick out by a person who is competent at tasting coffee. As easy as your red/white wine visual test. People in general are very bad at tasting and especially thinking and communicating about tasting. Plus also people may not know what decaf coffee tastes like or may have never thought about it before.