You’re probably ignoring the second most important ingredient in your coffee. Although coffee nerds meticulously select their coffee, equipment, and brewing techniques, most just use whatever water comes out of the tap. But water makes up more than 98% of filter coffee, so it shouldn’t come as a surprise that water can radically change the way your coffee tastes.
The chemical composition of the water both affects how the soluble coffee particles are extracted and how those flavors are perceived when consumed. For example, softer water will accentuate a coffee’s bright, juicy flavors, while water that is overly-hard will like taste flat and astringent. But it gets more complicated. As Maxwell Colonna-Dashwood and Chris Hendon explain in their seminal book, Water For Coffee, although water hardness is determined by the cumulative ppm of dissolved minerals, it doesn’t tell you what minerals are present. This matters because minerals like calcium and magnesium aid coffee extraction and don’t negatively affect flavor, but other minerals like iron and sodium bicarbonate can have an off-putting affect on coffee flavor. In other words, water matters.
While serious coffee shops spend thousands of dollars on their water filtration systems, for most consumers buying filtered spring water is the only viable option. But different brands and even different bottles of spring water can have very different chemical compositions depending on the source water. This problem bothered a couple of coffee-loving entrepreneurs in Southern Ohio which led them to create a product they call Third Wave Water….
