Passion, experience, and consciousness through coffee

How Hardness of Water Affects Coffee Brewing

Oct 16, 2013 • Brewing, Slider7 Comments

Coffee is mostly water. The quality of water naturally affects cup result. Coffee is often considered to be a water containing small coffee particles, but it is ideally a clean solution in which various tasty chemicals are completely dissolved. Except, the espresso is a colloidal solution which soluble and unsoluble matters exist in the liquid.

chemex coffee brewerThe ideal water for coffee is soft water which contains less minerals, rather than mineral rich hard water. The soft water with less soluble substance dissolved in is more capable to dissolve coffee nutrients. The hard water which already dissolved minerals within is less capable to dissolve substance in it.

The following article is a good example of how a coffee shop can actually prepare special water to differentiate the cup quality.
http://www.huffingtonpost.com/2013/05/30/starbucks-toilet-water-coffee-bathroom-hong-kong_n_3360341.html

Hardness of Water and Brewing Method

It is found interesting that coffee brewing methods are developed differently depending on the areas of the world. In Italy, where hard water is common, the espresso has been developed. While pretty much all the brewing methods started in Europe, espresso has been notably developed.

Japan, the place the most of contemporary pour over methods have been developed, has great access to soft water throughout its land. The two major coffee drinking cultures evolved based on their natural water quality.

But now is the time, coffee chooses water rather than water chooses coffee. The trend is shifting from Starbucks driven espresso to third wave driven pour-over, shift of hard water to soft water could be undergoing water trend.

Hardness of water you use

Technically, there seems to be other factors contributing to determine hardness of water besides minerals, but the following classification chart(from wikipedia) by United States Geological Survey gives a good idea.

hardness of water

If you brew coffee at home, knowing the water hardness in your area might be helpful.

There is some useful study I found about “Mineral Content of Tap Water in Major North American Cities”.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/table/tbl2

Or for the bottled water users, this study is useful.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/table/tbl3/

Comparing the tastes between hard water brewed coffee and soft water brewed coffee could be an interesting coffee science project.
(photo credit: rootseven)

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7 Responses to How Hardness of Water Affects Coffee Brewing

  1. Great article. We are crazy hard water where I’m from but it comes and goes. Same days it doesn’t affect taste, but other days it’s very noticeable.

    • Admin says:

      Garrett, thanks for your comment. I guess minerals in water could be easily affected by the temperature and weather.

  2. I’ve never been this happy to find such an interesting post. I love those coffee tips there. It’s so helpful. I’m gonna try some ideas of yours.

  3. Coffee guy says:

    Ideal ppm of water for coffee is 160-200 or more. This is considered hard water. Soft water overextracted most coffees.

    • Admin says:

      Coffee guy,
      Thanks for your comment. I assume hard water works better for regular coffee machines, but most major drip cones are designed for soft water. Other parameters affect the cup result as well.

  4. peter says:

    Water does affect to coffee quality, flavor. I must definitely check water if my coffee has strange flavor.
    Thank for you in-depth post.

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