Bitterness is the peculiar sensory characteristic of coffee. But why is coffee bitter and why do we like this typically unpleasant taste in our favorite drink?
The last step of coffee’s sensory analysis after the visual, olfactory and gustatory examination, concerns the taste or rather memory that coffee leaves in the mouth and inside the palate once your cup is empty.
This is called an aftertaste or finish.
What do we find in the aftertaste?
The aftertaste of a coffee is largely the product of all the sensory elements that we find in every sip. When we swallow all of these elements mix to form the aftertaste. In some way the “grand finale” of every coffee.
The acidity in the aftertaste can be crunchy and bright, or soft and clean. If excessively marked and prolonged, it can give a balsamic, almost spicy, burning sensation.
The sweetness is a pleasant element to find in the aftertaste. In the final stage of roasting, the caramelization of the sucrose present inside the bean takes place which gives pleasant and persistent notes of caramel, malt and dried fruit, together with a pleasant sweetness and oiliness.
The bitterness is a hint that we would not like to find in the aftertaste of our coffee. Most of the time it’s hard, pungent, and can also create a slight scratching sensation when swallowing. Generally, a very bitter aftertaste is the result of excessive roasting or excessive extraction.
Aromas are the most complex sensations to identify. When we swallow coffee, the aromas rise up to the nasal passages and are perceived by our sense of smell and interpreted by the brain as flavors. It is our olfactory bulb, through the indirect activity linked to swallowing, which helps us to distinguish positive or negative notes that remain inside the palate. Some components of the flavors left by the aftertaste can make us remember flavors such as chocolate (sweet), wood smoke or tobacco (burnt), spices (cloves), or pine sap (resinous).
The mouthfeel rarely contributes to the aftertaste as intensely as the other elements. However, coffees with particularly distinct sensations can be perceived especially if they have a heavy creamy body or juicy sweet.
When we drink the next coffee, let’s pay attention to each of these features and how they affect the aftertaste.
Sometimes we will not find them all, but other times they will all have a fundamental role in creating the finish.
The quality and persistency of the aftertaste
And then there is the quality of the aftertaste, a bit like the quality of the aroma in the olfactory phase, which evaluates the variety and finesse of aromas, of sensations that we perceive in the hollow of the mouth after tasting the coffee. It requires a few seconds of patience and concentration. At times, some sensations found in coffee in the olfactory phase can be enhanced in this next moment, others can be transformed and enriched.
Finally, the persistence of the aftertaste. We will go, with the passing of the minutes, to evaluate how long a sensation of coffee remains in our mouth. Some non-exceptional coffees may still have a prolonged persistence, which, in this case too, is not a sign of quality.
Aftertaste: bad experience or good memory?
Compared to other drinks, coffee flavours linger in the mouth for a long time (the aftertaste of an espresso can last up to 15 minutes) and this, depending on the quality of the coffee, may or may not be a good thing.
When the aftertaste is negative
It’s not just persistence that matters. It does not always go hand in hand with quality and, in the presence of the negative scents described above, persistence may not even be appreciated.
Unfortunately, it often happens that the meal ends with a coffee that’s not up to par and therefore a negative aftertaste remains in the mouth.
The emblematic example is coffee in a restaurant. Everyone prepares it, serves it and puts it on the menu regardless of the type of cuisine on offer. However, sometimes its quality is not in line with that of the cuisine or wine just tasted.
There are some sensations that we cannot define as pleasant, especially if their intensity exceeds a certain threshold.
For example, let’s think of bitterness, burnt or acidity sensations. When they are excessively marked and persistent, they do not give us a good experience.
When the aftertaste is positive
Sweetness, aromatic complexity and viscosity are therefore fundamental for the positive perception of the aftertaste. Pleasant and persistent notes of caramel, malt and dried fruit, together with a pleasant sweetness and oiliness are hallmarks of a stellar aftertaste.
The body of the coffee is also important, as the fuller the body, the more persistent the aftertaste.
A quality coffee will have a sweet, clean and persistent aftertaste without unwanted sensations which remains on the tongue for a variable time from 10 to 15 seconds after swallowing.
Absence of defects and prolonged sweetness are the key characteristics that will avoid an unpleasant “bitter taste in the mouth” finish.
Let’s think about the last coffee we drank. What memory did it leave us?