[nerdponx]

Quick ctrl-F reveals no mention of the word "grape" or "barley" in the article.

Nobody is surprised that genetically-similar grapes grown in different regions and converted to wine using different processes taste different. Same goes for barley and beer, apples and cider, et al. Why should we be surprised at all that it also happens with coffee?

Plus, small genetic differences can result in large physiological differences in the actual organism. Just look at broccoli and cauliflower, for example. Or domestic dogs, or humans.