The Secret to Awesome Coffee? It’s in the Water

By Carl Engelking | June 6, 2014 2:53 pm

pour-over coffee

Coffee, on its surface, is an incredibly simple beverage: just add hot water to ground up roasted beans. However — as in any great pursuit — achieving perfection remains elusive.

In the quest for the flawless cup of coffee, aficionados have looked at everything from roasting technique, to method of grinding, to the perfect ratio of water to coffee (said to be 17.42 units of water to 1 unit of coffee).

But less often considered is the water itself. While we tend to view tap water as a pure ingredient, it’s actually loaded with minerals that can influence coffee’s flavor. And now chemists have pinned down how the chemicals in different types of water interact with coffee beans to shape the taste of the brew that results.

Science to the Rescue

Coffee is loaded with a tremendous amount of natural chemicals and over 1,000 aroma compounds. Water, on the other hand, can be rich in minerals like calcium and magnesium if it’s “hard,” or if it’s “soft,” rich in sodium — used by water softeners to remove impurities.

For this study, Christopher Hendon, a chemist from the University of Bath, focused on the way different kinds of water affect the extraction of six chemicals that contribute to the flavor of coffee. These flavors included citric acid, lactic acid and eugenol — responsible for coffee’s “woodsy” taste. He found that magnesium in hard water, for example, sticks to eugenol, giving the resulting brew an even woodsier taste, Business Insider reports. And bicarbonates in hard water will make the coffee bitterer. The findings were published last month in the Journal of Agricultural and Food Chemistry.

“Hard water is generally considered to be bad for coffee, but we found it was the type of hardness that mattered – while high bicarbonate levels are bad, high magnesium ion levels increase the extraction of coffee into water and improve the taste,” Hendon told

Selecting the Right Coffee

Soft water, unfortunately, lacks the sticky minerals of hard water, so it’s poorer at extracting flavorful compounds. But if you live in a soft-water haven, don’t dismay: a tactical selection of beans may help counter the problem.

Just like one would pair wine with a certain type of food, the same is true for your type of water and the coffee you brew. You can get a rough idea about the hardness of your water by checking out the U.S. Geologic Survey water map. Then, purchase beans that are best brewed with hard or soft water, which a knowledgeable roaster should know.


Photo credit: Patrick T. Power/Shutterstock

CATEGORIZED UNDER: Health & Medicine, top posts
MORE ABOUT: nutrition
  • Longmire

    Next someone will realize that the soil and time of harvest have something to do with the taste as well, oh yeah and the idea of weather having something to do with it would sure up funding for the studies.

    • EdytaHusseinmuo

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    • SixSixSix

      Anyone familiar with good coffee knows that. But you do bring up that shifting weather conditions which are both disrupting the coffee supply especially with fungal diseases at higher altitudes in Central America, what coffee may grow best in a region, and which regions may grow the best coffees.

      Should you wish to live in a lovely temperate climate, here’s a hint. Make sure there are coffee plants nearby. Coffee likes year round temperature near 65F, just like people who live in San Diego. This can be found by a combination of how far north or south of the equator (generally with 9 degrees) and fine tuned by high up the mountain you go. Hawaii for instance is an oddity in that it is unusually far north but the coffee their grown at really low altitudes compared to most of the rest of the coffee world.The net result is that pampered coffee plant will grow best about at the temperatures which are the most moderate and most comfortable (although that does not guarantee the rainy season may not be a nuisance). See, one more reason to love coffee.

  • gogoboy

    Hmm! I thought it’s the size of coffee being ground, from coarse to fine etc. How interesting water also part of the secret.

    • SixSixSix

      If you buy industrial grade coffee in most grocery stores, nothing matters particularly much as it is already stale, and likely dreadfully over roasted should it have a mermaid on it, although the mermaid is actually a siren which is a mythical Greek beauty who entices sailors to their death with seductive songs, go figure why anybody would want that for a symbol! Drink up and enjoy boys, for tomorrow we all die.)

      • Heimdall222

        “…and enjoy boys, for tomorrow we all die.”

        Are you saying that all pedophiles will die tomorrow?

        • SixSixSix

          What? Did you cross post by accident?

          • Tomek Brzezinski

            No, they were making a pedantic grammer comment. There should be a comma after “enjoy” and I think that would fix it.

          • Heimdall222

            “…that would fix it.”

            You betcha.

            As our third-grade teacher always said — Commas are our friends!

            And BTW, that’s ‘grammar’. Pedantic, no?

            Oh, wait, maybe you were thinking of Kelsey Grammer…?

          • Tomek Brzezinski

            arrrgh, ok. I laughed at the grammer/grammar. My mistake.

            Whether it makes sense, or not, to be correcting people on the internet…everyone can decide that on their own. I personally think it’s not worthwhile.

          • Heimdall222

            “I personally think it’s not worthwhile.”

            Amusing, however!

          • Bonnie E Cowan

            ????????? O M G !!!!!!! What the heck is going on?
            Ahh back to the coffee topic…..
            All I can say using tap water ruins your coffee maker fast! Even if you clean it the minerals in the water distroy the machine. I like to use distilled water it tastes better to me and I’m not buying a new coffee maker every 4-5 months. No build up in maker using distilled water.
            😀 Just sayin….
            I prefer fresh ground coffee as well, just tastes fresh and clean. Mmmm coffee is good.
            Oh and sorry ahead of time for all the nitpickers out there for the POOR GRAMMAR! AHHHHAAA!!!!! LMFAO!
            Peace Out xx

          • Heimdall222

            “…the POOR GRAMMAR!”

            Or perhaps, ummm…the poor Grammer?

            Kelsey has, after all, been having his problems!

          • Bonnie E Cowan

            OOhhhhh welllll heeeheee!!!!!!

  • SixSixSix

    As first order cut the things that matter to a good cup of coffee are:

    1) the coffee plant and growing conditions (“farmgate” if you are serious)
    2) proper harvesting
    3) the immediate processing of coffee cherries into coffee “beans” (perhaps the most under-appreciated step)
    4) age of the bean (also assuming proper shipping)
    5) roasting technique and time (degree of roast)
    6) length of time after the roast (under two weeks unless vacuum sealed and frozen)
    7) grinding technique and time (roughly not more than 10 minutes until brewing)
    8) water (I personally NEVER use local tap water)
    9) brewing technique
    10) time before consuming (roughly no more than two hours or the fines over develop into a bitter taste; flavor can change remarkable over the acceptable time providing a range of tastes)

    • Smarter than Your Average Bear

      You forgot temperature at which it is brewed.

      • SixSixSix

        My bad. I should have made that clear under brewing technique, which more generally should be preparation technique.

  • swagv

    Uhh, “secret”? It’s mostly water to begin with.
    But what’s most foolish is the belief in a “perfect coffee” ideal. As Howard Moskowitz proved, that concept died with spaghetti sauce in the 1960s.

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      • Heimdall222

        Rhonda, Rhonda, Rhonda. TskK!

        Such a spammer you are.

        Flagged and down-voted for deletion.

        Deleted…wait for it… wait for it….

  • Heath James Cadriel

    Big shocker. coffee and whiskey are so similiar people over look it. All whisky distilleries plan the business solely around sources of good water. Next thing you know science will prove rh 68% is good for cigars

  • daqu

    Actually, the secret to awesome coffee is a combination of things: fresh beans freshly ground, good water without chlorine, and most overlooked of all: coffee equipment that has been thoroughly washed and rinsed clean, especially so that is has no buildup of coffee oils.

  • daqu

    “Just like one would pair wine with a certain type of food,”

    You mean “Just as,” not “Just like.” I expect better of Discover.

  • Sajida Hammad

    I read the article because I’m a coffee lover (I assume everyone here is) But I personally found all the comments to be hilarious, made coming here very nice.
    And about the coffee; tap water is fine, as long as you purchase freshly ground coffee, and mix the right amount of espresso in it.
    I recommend that you all try Turkish coffee, if you love coffee you’ll really enjoy it.

  • Michael Kurtz

    not to get too technical, but i went to a glass bottled water to do away with any plastic chemicals…most glass bottled H20’s are mineral water and i tried the one whole foods sells (at not a bad price)…the sparkling version on its own is great (galvanina from italy) but using the still (non-sparkling) version makes my coffee both bitterer and chalky…here’s the technical part in case anyone can translate this, the mineral analysis, but it indeed looks like it has the dreaded bicarbonates to the max:

    7.1 ph factor
    113 Calcium
    33 Chloride
    839 Conductivity
    365 Hydrogeniccarbonate
    20 Magnesium
    9 Nitrate
    1 Potassium
    33 Sodium
    89 Sulphates
    …any comment is appreciated.

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    my friend was searching for UT DOPL Delegation of Services Agrmnt a few weeks ago and discovered a great service that has an online forms library . If others need UT DOPL Delegation of Services Agrmnt too , here’s

  • Anonymous

    How can I find out more about this topic?

  • Kurt Wetzel

    I should experiment with this because I live in a city with nasty tasting tap water. It tastes heavily of metal and overall a bad taste. Its so nasty tasting I refuse to drink it and buy and drink bottled spring water.
    First I need to buy a new coffee pot since I have been using tap water to brew coffee. This way no leftover tap water taste or anything. It won’t matter as the coffee maker I use is only $10 at Walmart. Looks cheap but does not break it only has a off/on switch no fancy buttons like most coffee makers. Those fancy ones, from my own experience, do not last.


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