How to Make Coffee Less Bitter

Knowing the Term Perceived Bitterness
Why is My Coffee Bitter?
Steps to Making Coffee Less Bitter
Fun Coffee Bitterness Research

Knowing the Term Perceived Bitterness

There are hundreds of chemical reactions occurring during roasting and more than a thousand compounds are created as a reaction. Some of these compounds, such as trigonelline, caffeine, and chlorogenic acids, carry distinct bitter tastes and contribute to the perception of bitterness in coffee. The perceived bitterness in the mouth is linked to how much these compounds are extracted, which depends on factors such as the roast level, water temperature, brewing time, grind size, and brewing technique.

When balanced correctly, bitterness can complement coffee’s acidity and enhance its overall flavour profile. However, excessive bitterness can overpower other desirable flavours present in the coffee, leading to an undesirable outcome.

Why is My Coffee Bitter?

The answer is over-extraction. As mentioned in the upper paragraph, bitter coffee is usually an outcome of over-extraction. So, what causes over-extraction? What have I done wrong?

Grind Size: Hot water extracts desirable flavour compounds from coffee grounds during the brewing process. However, when the coffee grounds are finely ground, the soluble components within each particle become much more exposed to the hot water. This can lead to over-extraction, causing bitter components to overpower other flavour compounds.

Brew Temperature: During extraction, hot water plays a role in not only extracting compounds from coffee grounds but also in expanding and opening up each coffee particle. This expansion increases resistance within the filter basket, especially at higher temperatures where it occurs more rapidly. Higher resistance disrupts the water flow, allowing the coffee grounds to come into contact with the water for a longer duration, potentially leading to over-extraction.
[Click here to read ‘Brew Temperature in Espresso Extraction’]

Yield: The water-to-coffee ratio determines the overall flavour of the final cup: as each coffee particle comes into contact with more water, undesirable flavour compounds may be extracted during the later stages of extraction. If the yield is decreased, it can reduce the bitterness of your coffee.

Channelling: Channelling refers to the uneven or inconsistent flow of water through the coffee grounds during the brewing process. When water doesn’t distribute evenly and instead finds a path of least resistance, it can create channels or gaps in the coffee bed. As a result, some areas of the coffee bed are over-extracted while others are under-extracted, leading to an imbalanced and potentially undesirable flavour profile in the final cup. Uneven coffee distribution, tamping unparallel, and broken coffee puck are what may cause channelling.
[Click here to read ‘What is Channelling in Coffee Brewing?’]

Steps to Making Coffee Less Bitter

Grind Size: Adjust the grind size coarser to avoid over-extraction from each coffee particle.
Brew Temperature: Try decreasing the brew temperature by 0.5 degrees Celsius per experiment.
Yield: Try decreasing the yield (water out) to reduce the amount of the later stages extraction.
Channelling: Ensure even and consistent water distribution by studying proper tamping skill.

Fun Coffee Bitterness Research

Bitterness is diminished in coffee brewed with either soft or hard water when compared to distilled water.
The addition of sucrose, sodium chloride, or citric acid reduces the bitterness in coffee. Generally, hydrocolloids were observed to lessen the perception of coffee bitterness.
Robusta coffee contains elevated levels of both caffeine and chlorogenic acids, contributing in part to the bitterness in coffee.
Several researchers have determined that the processing method of coffee (wet or dry processing) does not impact the perceived bitterness of coffee, even though the overall flavour profile differs significantly.
Reports indicate that increased bitterness led to a reduction in the sourness of coffee.

Conclusion

In closing, our exploration of coffee bitterness reveals its intricate role in the tapestry of flavours that define this beloved beverage. Bitterness is not just a note; it’s a key that unlocks a realm of nuanced experiences. From its origins to the art of balance, embracing bitterness is embracing the depth of coffee itself, inviting us to savour each sip as a journey into complexity.