Let’s discuss what could happen when coffee is prepared with poor quality water. What follows are some possibilities using some radar charts as illustrations. In a radar chart, start reading at the top. The flavor attributes are listed on the outside, and the distance from the center indicates the intensity of the particular flavor attribute.
[figure 9] Caption: This is an illustration of a well-balance, high-quality brewed coffee with good sweetness and medium-high acidity.
In the illustration above, the coffee is pleasant because it is dominated by the aromatics, sweetness and acidity, with medium body. The salt/potassium aspects and bitterness are present, but at levels that do not dominate the overall flavor profile.
If you were to brew coffee containing high TDS, however, the flavor profile would change significantly.
[figure 10] Caption: Not as much flavor is extracted, in particular, the preferred flavor components.
In the illustration above, salts, which dissolve easily (additional salt may be present in the brewing water itself), completely dissolve and the bitter aspects solubulize more as a result of dwell time and action. The aromatic, acidity and sweetness attributes have not dissolved.
[figure 11] This illustration shows water used for brewing with a high (alkaline/basic) pH and/or high alkalinity, which directly affects the acidity of the brew.
In the illustration above, the aromatics are low due to the elimination of acetic acid and other aromatic acids. This results in a brew with low acidity. The sweetness is still present, but the balance of the profile tends toward the salt/potassium and bitter side of the chart.
[figure 12] This figures shows the result of brewing with salty or brackish water.
This last illustration is not as out of balance as some, but the acidity and aromatics are not perceived as clearly as the salt/potassium attribute. The result is a brewed coffee that is more bitter than sweet and acidic.
