Sugar in your coffee? Adding it is frowned upon, but what sugar does coffee already contain?

Sugar in your coffee? Hinzufügen ist verpönt aber welche Zucker bringt der Kaffee schon mit?

In western Austria, mountains are generally only recognized as such above the tree line. This phenomenon is unknown around the equator and therefore also within the coffee belt. Here, it's quite possible to find coffee plantations at altitudes of 2200 meters.

The term "highland coffee" for C. arabica varieties is indeed fitting. The C. canephora genus, widely known as Robusta, is traditionally found at lower elevations, up to 800 meters. However, even this is no longer a universal rule; this genus has been "migrating" to higher altitudes in recent years. C. canephora plants can now be found at elevations as high as 1500 meters. Does all this have an impact? – Quite a few! – One example can be quickly explained. An Ethiopian-Belgian team of scientists (Worku et al., 2018) described several aspects in a very readable publication. In summary: the sucrose (sugar) content of the green bean correlates positively with the altitude at which it is grown.

This means that if the same coffee variety is grown at different altitudes, higher sucrose (and also glucose) content can generally be expected from the coffee beans grown at higher elevations. This phenomenon is currently attributed primarily to a combination of cooler temperatures, a slower ripening process, and simultaneously more intense sunlight. Sucrose undergoes numerous transformations and breakdowns during roasting. Many desirable flavor compounds are produced in the Maillard reaction and through caramelization – processes in which sucrose or its constituent sugars, fructose and glucose, are involved. And believe it or not, various acids are formed in the bean from sucrose and other sugars during roasting: formic acid, acetic acid, and lactic acid, to name the most important. These reach their maximum concentration at a certain point during roasting and are subsequently partially broken down.

Additionally, green coffee beans also contain significant amounts of citric and malic acid – like many seeds from other fruits. The natural "green" acidity increases further with altitude, especially when the coffee plants are shaded from direct sunlight by trees. This interesting blend of diverse aromas and acids contributes to the exceptionally complex and rich aroma and flavor profile of coffee extracts.