Coffee is pretty much the life blood for most of us, especially if you find yourself reading this article from work on a Monday morning. We drink it primarily for the caffeine, but at the same time, a great tasting cup of coffee can warm the soul. Recently however, a chemist may have discovered why we’ve been making coffee all wrong; there is one thing we all do that may be preventing us from brewing that great tasting pot of coffee. Hint- it has nothing to do with the coffee beans.
Christopher H. Hendon is a PhD student in theoretical and computational chemistry at the University of Bath. Sitting in a coffee shop, he overheard a problem between two baristas over why their coffee tasted good one day but not another. He set out to find out why and discovered the key ingredient to great coffee- it’s the water.
Now most of us basically know two types of water- tap water, which we know has a bunch of minerals in it, and filtered water, the pure, tasteless water we get from our Brita filters and the like. Most of us would think using filtered water to make our coffee is better because it’s “cleaner,” but that’s actually the most common mistake we make and here’s why.
Hendon teamed up with baristas Lesley and Maxwell Colonna-Dashwood and discovered that it’s actually tap water, aka hard water, that brings out significantly different tastes in coffee. Roasted coffee comes packed with compounds like citric acid, lactic acid, and eugenol, which brings out the woodsy taste we all like in our coffee. Hard water contains different levels of ions like magnesium and calcium that stick to compounds to enhance certain flavors- the higher the levels, the harder the water. For example, magnesium in the water will actually help brew coffee with a stronger flavor with higher levels of caffeine. However, water with bicarbonate will make bitter flavors stronger in coffee.
Using filtered water, or soft water, won’t make any flavors stick out particularly, but it gives a uniform taste for all different kinds of beans (Starbucks does this for their coffee since their beans come from all over the world). This might all sound very sciencey, but if you are looking to bring out the best tastes in your coffee, you can look up what your local tap water has in it online (you are looking for high-magnesium, low bicarbonate) or even buy specific coffee beans for the kind of water you have.
So if you are making coffee this morning, instead of using filtered water, try using tap water and see if you can notice any new flavors coming out. Cheers!