What determines the sweetness of coffee?

It's not just when it comes to coffee: sweet tooths have a weakness for sweetness. This is also very important for a balanced perception of our flavour. We have always associated sweetness with positive things. We are born with this weakness for sweet energy.

Coffee plant determines amount of sugar
The ingredients of the green coffee bean are 50% carbohydrates, i.e. arabinose, mannose, glucose, sucrose, galactose, rhamnose and xylose. These are only partially soluble in water and are therefore only partially contained in the prepared coffee. The amount of sugar in coffee varies depending on the type of coffee plant. Robusta coffee varieties have only half as much sugar as Arabica beans. These are therefore more popular and, depending on the subspecies, more or less sweet.

It all depends on the processing
The sugar content of coffee depends on how it is processed. If coffee cherries ripen slowly, the sugar content is correspondingly high. This is particularly true for coffee grown at high altitudes. Semi-dry coffee has more sweetness than washed coffee. The ripe cherries dry specialists with the fruit mucilage, but without the pulp. The fruit mucilage, also known as mucilage, which consists of pectins and a lot of sugar, is largely responsible for the sweetness of the coffee.

Sweetness as a quality feature
A certain sweetness characterises Arabica coffee. Otherwise, the manufacturer may have processed unripe coffee or prepared it incorrectly. The rating of green coffee is particularly high if the sweetness is present. The roasting process and the preparation of the coffee also influence the sweetness. The perceived sweetness of coffee varies depending on the consumer and their taste buds.

How sweetness is created during the roasting process
During roasting, several organic compounds and other complex products are formed in the so-called Maillard reaction. This is the browning reaction of amino acids with sugars in reduced form. Sugars caramelise during the roasting process. The longer this takes, the less long the sugar molecules precipitate. The caramel compounds are then very bitter and extra complex.

The perfect sweet spot
In sensory terms, a sweet spot is the exact centre point between bitterness and acidity. A barista creates a perfect coffee when he or she perfectly balances under- and over-extraction during brewing and also hits the right strength. If the grind is too fine, the result is over-extraction. If the powder is very fine, this means that the water has to overcome greater resistance. The barista then extracts more powder than intended. The result: the flavour is bitter and unbalanced. If coffee is under-extracted, it tastes sour, aggressive or grassy. This is due to a coarse grind, where too little is extracted from the bean. The golden mean or sweet spot is achieved by experienced and skilled baristas who enjoy experimenting.

Conclusion
Sweetness also gets into the coffee when connoisseurs add a lot of sugar to their drink. They often do this with low-quality Robusta blends. In most cases, however, this is a bad habit on the part of consumers. A perfect coffee prepared by a professional is a real treat without adding sugar. Let yourself be surprised and discover the natural sweetness of your coffee.