if your water tastes weird by itself, it will not become innocent when coffee gets involved.
start with fresh, cold drinking water that tastes clean and does not smell like chlorine.
for a lot of people, filtered tap water is the easiest answer. a basic carbon filter can reduce chlorine and some off smells. it does not make every city's water identical, but it can be a very useful first move.
i would not automatically use straight distilled water.
coffee extraction needs some minerals to work well. water with almost no minerals can make coffee taste flat or strange. very hard water creates the opposite problem: it can mute flavors and leave scale inside your machine.
this is why the most expensive bottled water is not automatically the best coffee water. mineral labels are not a ranking system.
try a simple side-by-side test. brew the same coffee with your tap water and with filtered water. keep the coffee, grind, ratio, and method the same. taste them after they cool a little.
if one cup is clearly sweeter, cleaner, or more balanced, you just learned something useful about your water without starting a chemistry degree.
for espresso machines and automatic brewers, also check the manual. some machines have water-hardness settings, filter instructions, or limits designed to protect the machine from scale.
if your filtered water still makes dull coffee or heavy scale, then it may be worth trying a coffee-specific mineral packet with distilled or reverse-osmosis water. follow the packet directions. do not freestyle minerals into the kettle.
tl;dr: use fresh water that tastes clean. filtered tap water is a strong place to start. avoid straight distilled water as the automatic answer, and watch very hard water because it can hurt flavor and build scale.
we pay attention to the water at Couplet so your coffee can taste like coffee.
coupletcoffee.com / @couplet
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