The Impact of Water Quality on Coffee: Which Factors in Water Affect Coffee Extraction Experiments

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FrontStreet Coffee's Scientific Explanation: The Impact of Water TDS on Coffee Extraction

It's time for FrontStreet Coffee's scientific explanation session, this time discussing the impact of water TDS on coffee extraction. Does it sound mysterious? How can making a cup of coffee require some understanding of chemistry? This understanding is correct, otherwise why would coffee be considered a rabbit hole? Because there's more than one aspect to fall into...

Minerals in Hard Water: The Impact of Water Quality on Coffee

In water science, water is no longer just H2O. Drinking water is a complex mixture containing various minerals (sodium, potassium, magnesium, calcium, chloride, and other ions). Coffee beans have an impact of over 80% on the flavor of this cup of coffee (otherwise, why would it be called drinking coffee—), but the remaining 20% is also crucial.

Our research reports indicate that water quality has significant differences in coffee flavor. This is because water carries these phenolic compounds, organic acids, and other coffee substances—not simply dissolving in water for us to drink. This involves the chemical and physical changes in water science for coffee, which in turn affect sensory factors such as aroma, flavor, and body.

However, water source control, quality management, and other water quality indicators are not something that regular shops or enthusiasts can control. But today, through scientific evidence and effort, the above factors can be overcome, which is also the reason for the new wave sweeping in. Perfect beans need suitable water quality, and secondary-grade beans need water quality that can unlock their potential even more.

From green beans (origin) → roasting (talent) → extraction, in this era of coffee bean explosion (where both origin and talent are built-in for you), what we can choose is to select the right water quality (battlefield) for it. Just as people need to develop according to their aptitude, so do coffee beans. Different tonality beans require different water quality. Hardness levels of 20-300 ppm, differences in ion concentration (amounts of potassium, magnesium, sodium, etc.), carbonate, and sulfate groups are all variables.

For light and medium roast coffee beans, light roasts require slightly lower water hardness of 60-250 ppm.

Medium and dark roast beans require higher hardness of 100-300 ppm for better extraction efficiency and mouthfeel.

Water quality differences (hardness, minerals) may vary by region, thus creating coffee with regional characteristics. Using scientific methods to correct these differences and extracting beans with the correct water quality is the perfect and non-wasteful approach to coffee beans!!

Water quality differences (hardness, minerals) may vary by region, thus creating coffee with regional characteristics. Using scientific methods to correct these differences and extracting beans with the correct water quality is the perfect and non-wasteful approach to coffee beans.

Another factor of water's impact on coffee is water temperature. We can easily discover that the higher the water temperature, the more flavor substances are extracted from the coffee. Conversely, the lower the temperature, the fewer substances are extracted.

So besides water temperature, water quality also affects coffee taste and extraction.

Experimental Design Process

Test the TDS values of three different waters respectively, and brew using these three different water qualities. Taste by slurping with a cupping spoon.

This experiment uses FrontStreet Coffee's "Flower Champion" for demonstration. The coffee bean information is as follows:

Water Quality Test Results

Experimental Results

Water quality directly affects all coffee's taste, aroma, consistency, and many other health elements. The key influencing factor lies in the mineral composition of the water. Minerals such as calcium, magnesium, sodium, and potassium ions in the water affect the thermodynamic extraction capacity of coffee, thereby causing changes in coffee flavor.

Important Notice :

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