A historical survey of coffee aroma research

For about two hundred years attempts have been made to isolate and identify the constituents of coffee flavor or, at least, by the end of the Eighteenth century, to prepare extracts for the purpose of identifying its principes immediats (fundamental principles). In his Systeme de Chimie, Thomson (1807) wrote that chemists have performed many experiments to ascertain the constituent parts of coffee and its qualities . He mentions the work, now only accessible with difficulty and of pure historical interest, carried out by such scientists as Neuman, Geoffroi, Dufour, Kruger, Westfeld and Herman. The state of knowledge in the early Nineteenth century was summed up as follows  

Robiquet and Boutron (1837a,b,c) also considered the question of whether the characteristics of coffee are due to one principle or a set of components. While everything remained to be discovered, they display an alarming pessimism in observing  

We will pass rapidly over all these facts because, there being nothing in them which suggests to us the solution we seek to the problem, it becomes pointless to look any further. We also tried, with just as little success, some other avenues it is necessary to know to save our successors from treading them. It was claimed that roasting developed new principles, and it has often been repeated that heat releases an essential oil which is the real source of the entire coffee fragrance. 

To open a parenthesis in an anecdotal vein, a scientifically questionable and somewhat naive communication on the roasting of organic bodies was published in 1844 by Freiherr von Reichenbach, an 

We do not know the process that takes place in malt-drying—Indeed, do we even know what bread really is —Let us 

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