For millions of us, we couldn’t even imagine starting a day without a strong cup of coffee. But while we might argue passionately over the benefits of our flat white, espressos and mocha lattes against other coffees, all coffee is around 98% water.

No matter how great you might be at brewing the perfect coffee with the best gear, the freshest beans, and the strongest flavours if the water you’re using isn’t fresh and clear, then the finished product is never going to be up to standard.

What’s in the water?

You might not believe it, but a coffee made in exactly the same way with exactly the same beans can taste completely different if brewed with different water. Try it yourself if you don’t believe us. Try once with tap water and again with bottled mineral water or freshly filtered water. You might be shocked by the difference in flavour profile, texture and even smell.

This is because water essentially acts as a solvent when combined with your coffee which extracts the flavour of the beans. So, the perfect brew needs the perfect water but what does the perfect water look, feel and taste like?

Hard and soft

Water is either hard or soft based on its mineral content and the best water for coffee has a perfect combination of these minerals (mostly magnesium and calcium). The balance in these minerals needs to be perfect to extract the right amount of sweetness and bitterness from the beans.

While a water softener will certainly clear up your water it might also get rid of many of the minerals that the coffee needs to release the flavour of the bean. The same is true of purified water, which you’ll often find in a plastic bottle from the supermarket. Filtered water, however, simply removes the impurities from the water, leaving most of the natural minerals in place.

What does good coffee water taste like?

Good water for coffee should taste of very little at all. It should also be clear and free of odours or colours. If you really want to get scientific, the pH level should be as close to 7 (neutral) as possible and you’ll want to look for around 10 mg/l of sodium, 40 mg/l of alkaline and 0 chlorine. Of course, you’ll need a water testing kit to assure this but if you are using a decent inbuilt filter then you shouldn’t even need to measure it; the water should be perfect for coffee.

So, the next time you start up a brew and are happy to use just any old water, think again. Ask any expert barista and they’ll tell you the same thing – the beans might be the heart of the brew but the water is the soul, the blood and just about everything else!