One of the important stages that Q graders usually perform to test the flavor of coffee, especially specialty coffee is the coffee cupping process. This process involves observing and assessing various aspects of coffee such as roast color, aroma, clean cup, balance, uniformity, body, sweetness, acidity, and coffee flavor.

Especially for the flavor part, the taste and aroma of coffee is very important because it is arguably the first part of coffee that will attract the attention of coffee consumers.

Flavor defects that indicate bad aroma and taste in coffee are highly avoided in this coffee cupping process.

In this article, we will learn some examples of flavor defects that are often encountered in coffee cupping assessment. Theseflavor defects may arise due to natural factors or due to mistakes made during the coffee growing, processing, and storage stages. What are they?

Over fermented

The first example of a flavor defect is over fermented. This flavor defect is characterized by an unpleasant sour taste in coffee. Over fer mented can appear in coffee defects classified as full black, full sour, fungus damage, dried cherry, broken, floater, and hull.

Over fermented flavors usually appear due to several mistakes made during the processing stage, especially in the fermentation stage of wet-process coffee.

Keep in mind that the duration of time given during the fermentation process is crucial, as it can affect the flavor and aroma of the coffee.

When fermenting, one of the main objectives is to remove themucilage layer on the horn skin. However, this can be fatal if done for too long even after the horn skin is no longer slimy. The reason for this is because of the possibility of the coffee giving off an over fermented flavor.

If the fermentation time is done properly, the coffee certainly has the potential to bring out the fruity and sour flavors as expected. However, if the fermentation is done for too long, a sour vinegar-like flavor may even appear in the coffee.

To minimize any possibility of over-fermented flavor in coffee, it is important for farmers or processors to pay attention to several aspects such as how the coffee is harvested (do not select over-ripe coffee cherries), the length of fermentation time, and also the calibration of pulping and hulling machines.

Read also: Peel Through 3 Examples of Primary Defects in Coffee Beans [Part 1]


Moldy coffee is also an example of a flavor defect. This flavor defect has an impact on the sensation of bad taste and aroma in coffee.

To avoid moldy flavors in coffee, some important aspects in the farming and processing stages can be specially farmed by farmers or processors.

This compound can cause several risks of diseases such as headaches and stomachaches.

For farmers, for example, it is important to pay attention to the location and climate of the area where coffee will be grown. Hot and humid areas need to be avoided as they are more potential for mold growth on coffee beans.

The drying process also needs to be carefully considered. If the coffee beans are not dried with the appropriate moisture content, which is around 10-12 percent, then the possibility of mold growing on the coffee beans becomes even greater.

Both of these precautions are important. Although it does not directly affect our health, some cases indicate that the mold on coffee beans can produce a toxic compound, mycotoxin.

Read also: Thoroughly Review 3 Examples of (Other) Primary Defects in Coffee Beans [Part 2]


Another example of flavor defect in the coffee cupping assessment process is chemical/medicinal.

flavor defect
This flavor defect is characterized by the sensation of coffee tasting like a drug or chemical compound.

There are several factors that can cause this flavor defect to be present in coffee. For example, the error factor during the processing stage and also during the storage of coffee beans.

To prevent this from happening, it is important for processors to pay attention to the container and storage location of the coffee beans. In storing, coffee beans should not be placed near chemicals or objects with strong odors. The sacks used for coffee storage should also be clean and not used to store fertilizers/other materials.

Also make sure that the coffee beans are not kept in a plastic bag for too long or at too high a temperature. Proper storage is important to minimize the possibility of chemical/medicinal flavor sensations in coffee.

Also read: 4 Examples of Secondary Defects in Coffee

Potato defect

Potato defect, which is characterized by a raw potato-like coffee flavor, is also an example of a flavor defect.

Unlike other flavor defects that generally occur due to errors during the processing stage, potato defects actually have no direct relationship with the coffee processing stage.

flavor defect
Potato defects usually occur due to insect attacks on coffee cherries.

When insects such as antestia(Antestiopsis orbitalis) damage the outer skin by making holes in coffee cherries, bacteria are very likely to enter and make the coffee beans have a flavor potato defect.

To avoid this flavor defect, sorting to separate insect-affected coffee beans is important.

Chelsea Thoumsin in her research on potato defects also explained that since the chance of getting a potato defect is very small, it is the barista who can act accordingly.

Baristas can prevent the defect from spreading to other batches by flushing the grinder using different coffee beans that are free from contamination.

Read also: Get to Know More About Specialty Coffee, High Quality Coffee with the Best Quality Standards


Coffee cupping tests also classify baggy as one part of the flavor defect.

This flavor occurs when coffee beans are stored for too long and in poor conditions. In the case of baggy, the coffee beans will usually absorb the aroma of the storage bag (generally a gunny sack), resulting in a bad smell. Baggy also often causes a loss of flavor in the coffee.

To prevent this flavor defect, first ensure that the coffee has been stored in a dry and cool place. Also use clean, uncontaminated storage containers. Finally, make sure that the coffee beans are not stored for too long.

So, those are five examples of flavor defects that are often encountered in the coffee cupping assessment process.

From the five examples above, we can conclude that to get a good coffee cupping score, farmers or processors need to pay attention to the stages of coffee starting from farming, processing, and roasting. This is done because each stage can affect the presence or absence of flavor defects in coffee.

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