If immediately to the point, then coffee is best brewed on the maximum “clean”, you can say – poor minarals water. The fact is that the minerals will affect the taste of the coffee in the cup, respectively SCA (association of rush coffee) recommends brewing coffee on such water, the content of trace elements in which will not affect the taste.
And then it’s interesting. Coffee, like any stimulant, is dehydrating. It is known by everyone who got over the day before with alcohol – the legendary morning “drying” is nothing but dehydration. Therefore, taking this opportunity, it is recommended that alcohol too be filled with water (in many Western films there is a scene when the hero walks into a bar and orders a whiskey and a glass of water, it is just to avoid dehydration, we don’t have this practice yet).
Back to coffee. So, you drain the calyx, and soon in your system there will be unheeled dehydration. Along with the water will leave some trace elements. And here’s the focus – to make up for them, it’s best to drink a glass of water rich in minerals and all trace elements. But it is not possible to brew coffee on such water! Especially if we are talking about expensive and/or rare varieties of coffee, because this set of micronutrients will bring the taste profile of your coffee to the unknown side. Coffee should be sweet and tart, reminiscent of the tincture of prunes – will become salty and sour. In coffee jargon such overly sour coffee is sometimes called pardon, urine of old kirgiz cold-pressed. Or, say, coffee is intended to be a pronounced chocolate one resembling cocoa, and on rich minarel water there will be an almost elusive, barely noticeable shade of the baddest, brandy chocolate in half with milk buttermilk.
Therefore, the rule is: brew coffee on the most clean water, and drink coffee – the most mineral rich water.
How do I know what the water is? Very simple – all the information is listed on the label and counterlabel, important indicators
for brewing coffee:
– total number of dissolved particles (total mineralization, TDS), permissible up to 120 mg/l;
– calcium stiffness, permissible up to 70 mg/l, better – less (sometimes found and 20 mg/l)
– total alkalinity, permissible 40 mg/l;
– pH: 7;
– Sodium: 10 mg/l.
An important addition about calcium stiffness: it indicates both calcium and magnesium content. The latter shouldn’t be too much in the water you brew coffee on, but you don’t have to try to minimize it because magnesium in the water helps to “pull” the valuable apple out of the coffee acid. For example, coffee from Kenya is rich in citrus acid (if without details – there is such soil, so coffee from Kenya, if properly brewed, will be very citrus, like grapefruit juice). But, for example, washed coffee from Ethiopia is just dominated by lime notes in taste, it is because of malic acid. To catch the nuances of taste, you need to brew coffee with the right water.