Many heated words have been exchanged on the subject of the perfect cup of coffee, but could it just be something in the water?

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Image: How to make the perfect cup of coffee

Aleks / CC BY-SA 2.0 / Flickr: Toastkid

Calling all coffee connoisseurs! Forget expensive machines and bespoke bean blends, if you want to get your flat white right, the secret lies in one very simple ingredient: water.


Experts used computer modelling to examine how much of an impact different types of water had on the flavour of the coffee. The answer? Well, a lot, with a certain type of reasonably hard water topping the taste charts.


What is hard water? It's water with a high mineral content, so now you know. Hard water with high levels of sodium (which you'd get if you use water softeners) gets nil points for coffee-making according to chemist Christopher Hendon from the University of Bath. So what sort of water do you want for the very best coffee?


“Coffee beans contain hundreds of chemicals; the precise composition depends on the type of bean and how it is roasted," Hendon told the Journal of Agricultural Food Chemistry.


"The flavour of the resulting coffee is determined by how much these chemicals are extracted by the water, which is influenced by roast profile, grind, temperature, pressure and brew time.


"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."


So there you go. If you live in an area with the right sort of hard water your coffee will taste gooood. Enjoy!