Great grains, perfect toasting, excellent machines or utensils, grinding calibrated for the chosen method. All right to enjoy a good coffee, right? Perhaps. If you have reached the end of the process and have felt the bitter coffee, know that it may be the fault of the water.

Essential for brewing, water must also have quality – it is the most important component of coffee, accounting for over 97% of its composition. This is because your taste may change depending on the weather and the treatment given in urban areas. As water quality is a fundamental factor in the preparation of a coffee, and can transform even a microlot into a horrible coffee, you must be aware of aspects that are very important in this regard. And that’s about them we’ll talk about now.

Water filtration and temperature must be observed to avoid bitter coffee.


The most common mode of water treatment uses strongly alkaline substances such as lime, chlorine and fluorine. And very alkaline water has an effect on coffee brewing, especially when it removes its acidity. In addition, these substances enhance the perception of bitter taste when coming in contact with caffeine.

Another consequence is seen in espresso machines: alkaline water is a big problem, requiring extra care and treatment so that the equipment is not compromised.

To alleviate the ‘bitter coffee’ problem, you need to have a good household filter that can change the pH from very alkaline to slightly acidic – clay doesn’t solve this problem because it only removes dirt. To guarantee a good preparation of your coffee, the tip is always to use mineral water.


Crucial point: boiling water burns coffee! So it’s no use wanting to get the bad taste out of tap water by letting it exceed 100ºC. You will only double the problem and have a bitter coffee just the same.

The ideal temperature to bring the liquid in contact with the coffee grounds should be around 90 ° C, near the boiling point. If the temperature is lower, the coffee will be under extracted and will not release all the flavor and aroma that would release if the water was at the ideal temperature. In case of higher temperature, the water loses its oxygenation and the coffee will be over extracted, releasing not only the desired but also the unwanted flavors, such as exaggerated bitterness.

The tip for not leaving the coffee bitter is to remove the water from the fire when the first balls begin to come out. In the case of espresso machines or other domestic coffee makers, rest assured: they are already programmed to heat water without exceeding 90ºC.