The Best Water for Coffee Brewing

When it comes to brewing coffee, there are many factors to consider. It might feel a bit daunting at first to know what brew method to select or how to consistently prepare the perfect cup of coffee at home. From grind size to water quality, any number of variables are at play and have a direct impact on taste. And, we often overlook one of the simplest steps when making coffee: choosing the best water for brewing.

This guide seeks to inform which water qualities are best for providing a uniform yet complex coffee experience no matter your preferred extraction method.

How does water affect taste?

Before we get into the ins and outs of water quality’s effect on coffee taste, it’s worth highlighting that where you live can tell you a lot about the water you consume on a daily basis. For example, one big reason coffee might taste different depends on if you’re using tap or filtered water. More specifically, if using tap water, taste will vary depending on your water’s hardness levels. That is, the level of mineral content in it.

Hard vs soft water

Hard water refers to water that contains high mineral content as a result of percolating through sedimentary rocks (limestone, chalk, flint and sandstone). The high levels of calcium and bicarbonates in hard water show up as limescale.

Soft water, on the other hand, is simpler in its composition: it contains no dissolved calcium or magnesium. Instead, it contains high concentrations of sodium. An example of soft water is rainwater as - when it falls - this water reaches reservoirs in virtually the same condition. Hard water takes a bit of a longer route to reservoirs and brings along a few bits of sediment from its journey into our homes.

Which one’s better for brewing coffee?

So, this brings us to the important question: which one’s better? Well, you can’t tell the difference between hard and soft water just by looking at or smelling it. But, when it comes to brewing coffee, you can certainly tell (and taste) the difference!

Using filtered or soft water with a bit of hardness is ideal because its lower mineral composition doesn’t mask or overpower your coffee’s unique flavour but provides enough friction for extraction. If soft water is not available to you, opt for a carbon-activated filter (like Brita) or bottled water.

The right water temperature

Top tip before we get started: As a general rule of thumb: boiling water is rarely (if ever!) good for your coffee.

Getting the right temperature is crucial to brewing a delicious, complex tasting coffee. Too hot and you risk ending up with a bitter-tasting, over-extracted cup; too cold and you’ll have to sip on a flat, often sour, under-extracted coffee!

The recommended temperature for brewing coffee is between 195 to 205 degrees Fahrenheit (or 90.5 to 96 degrees Celsius). Similarly, if brewing coffee manually without a temperature gauge, let any boiling water slightly cool down before using it.

If you’re not sure why your coffee still tastes bitter or flat after taking the necessary precautions with water type and temperature, consider brewing time. If it’s too long or too short, you risk over or under-extracting the coffee, and neither is optimal for taste or a consistent brew.

Another key impact of how long you should brew your coffee for is grind size. For example, if you’re experimenting between grind sizes, the general rule to follow is fine for espresso and coarse for French Press or filter. It’s crucial to remember that an even grind is as important as brewing time and we recommend an all-round electric burr grinder (like the Mahlkönig X54) to consistently provide a uniform grind for your preferred extraction method.

Once you’ve gauged which grind size is right for your extraction method, measure out the amount of water you’ll need for your coffee. The recommended ratio is approximately 60 grams of coffee per litre of water, but this will depend on how you like your coffee. Adjust to your liking if you’d prefer a softer or stronger-tasting coffee.

Finally, whether you’re making an espresso or opting for filter coffee, make sure you enjoy your first sip while it’s hot. In other words, sip as soon as you’ve poured yourself a cup as coffee cools down quickly!