Our first 2024 “RE: Summer Series” is all about the one ingredient that comprises 98.5% of our cups of coffee… water! While easily overlooked, water quality can greatly influence the amount of coffee flavors extracted from your beans. The right water can enhance the coffee's natural characteristics, while poor-quality water can result in a flat, bitter, off-flavored, or unpleasant cup. In this article, we’ll explore the 3 scientifically-proven elements in your water that can significantly impact your coffee brewing: purity, hardness, and pH.
These 3 attributes are officially recognized in the Specialty Coffee Association Brewing Water Standards as follows: (1) Purity (clean odor, zero chlorine); (2) Calcium Hardness between 50-175 ppm; and (3) pH 7-8.
Purity
Water purity is an essential factor for any great cup of coffee, and one you can easily influence with a good water filter! Chlorine and other impurities can impart undesirable flavors to your coffee, and contaminants can lead to off-flavors. Spring, bottled, or a good filtered water has always been - and will always be - behind any great cup of coffee you’ll ever brew!
Hardness
Water hardness refers (primarily) to its magnesium and calcium content (aka multivalent cation concentration). This means, a water that is “hard” will have many cations, and a water that is “soft” won’t have as many. Why are they so important? They’re important because the flavor compounds in coffee happen to exist as aprotic, charge-neutral species and as a collection of acids and conjugate salts - all of which need cations (i.e. the Mg+ and Ca+ in your water) to extract into your brew! If water is too soft (i.e. has too few cations to extract), your coffee won’t taste so good! There is, however, a limit to how hard you’d want your water to be, particularly if you care about the longevity of your coffee equipment - if the water is too hard, these cations have a tendency to crystallize inside your machine and within the pipework, blocking flow, causing corrosion and leading to an eventual “early death” for your brewers, particularly Espresso brewers. Most studies agree that 50-80 ppm CaCO3 hardness is ideal for both flavor and equipment performance. The easiest way to know how “hard” is your local water (without testing it yourself), is to search for “City, State Water Quality Report Hardness” - one of the first results should be the most recent test that your City conducted (in Lakeland, our water is around a 150 ppm - still within the SCA ideal standard, yet hardly ideal for our equipment… which is why we must de-scale them periodically!)
pH
pH is the indicator of acidity or alkalinity - below 7, it indicates an acidic solution, and pH greater than 7 indicates an alkaline solution. For coffee extraction, the amount of flavor extracted increases as the pH increases until you reach very high alkalinity, which can lead to chalky flavors being extracted. A neutral to slightly alkaline pH, between 7 and 8 has been consistently found to be best. Again the easiest way to know the pH of your local water (besides a water pH meter) is in your City’s Water Quality Report (in Lakeland’s most recent report it was 7.8)
We hope you enjoyed learning about water today, and please know we always welcome your questions and topics for future articles… we’ll also be doing technical “Summer Series” on FB/Instagram (@ethosroasters) starting this week, so we hope you’ll enjoy those short videos as well! Oh! And the new 2024 Ethereal Summer Blend just launched and will be with us for the Summer… and since I’m already running a bit long here, please find all the details online (ethosroasters.com and on this month’s “Greatness Times”)!
Love Brewing Greatness with you,
Lisbeth
Sources & Further Reading