2 Best Reasons to Use Filtered Water for Brewing Coffee, According to Experts
There’s no shortage of tweaks you can make, even without extensive barista training, to move your coffee up to professional-level quality. As something that happens at the beginning of the day for most of us, and maybe several times a day more (depending on your caffeine addiction), why wouldn’t you want your coffee to be perfectly on point? It’s about setting the tone, more than the basic, mandatory caffeine.
If you’ve done everything you can: buy freshly roasted and locally sourced beans, grind them correctly, consider your brew rate and use the best brewing method, and your coffee still doesn’t pass the vibe test, what else can be done?
However, you may have to turn to another major source in your coffee game: water. I spoke with Jose Lepe, Director of Discovery and Quality Coffee for Sightglass, about how what goes into the reservoir or kettle affects your coffee outcome as much, if not more, than what goes into the grinder.
How water affects the taste of coffee
Many naturally occurring odors, metals and flavors are not removed from water simply by boiling.
Even if you odor or taste in your tap water it’s not boiled during coffee making, and your dark roast isn’t strong enough to compensate for the tasteless water. “There are different things found in municipal water that have a certain smell,” said Lepe. So you should filter your water especially to remove flavors and aromas.” A metallic tang, hardness or hint of chlorine or other chemical taste, even if it’s just a little, can be a sign that it’s time to try filtered water in your coffee.
Not everyone should do this, however, if your tap water tends to be neutral or clean. “A lot of the best coffee cities in the US — Portland, Seattle, San Francisco, New York — all of those places have amazing water,” Lepe said, “so if you make coffee with it, it’s going to taste great.”
If you live somewhere with good tap water and still aren’t satisfied with your coffee, you may need to go back to the drawing board on beans/grind/processing/measurement/temperature. But if this applies to you so far and you live somewhere with poor tap water, read on.
Mechanical considerations with water
Another consideration that doesn’t affect taste is how your water can affect your coffee brewing equipment.
For those who pour water, “if you use a kettle to boil water regularly, you will see a build-up of scale on the bottom,” explains Lepe. “The white stuff is usually calcium or other mineral deposits.”
Scale formation is greatly reduced when you switch to filtered water.
Descaler tablets they can easily be used to adjust your kettle, but you may also want to try using them in your automatic drip or espresso machine.
Depending on the water quality where you live, the build-up of minerals can be so bad that it causes your equipment to stop working altogether. A serious consideration, especially if you’ve invested in high-end equipment. “If our reverse osmosis system in our cafe in Los Angeles breaks for any reason, and we open the water passage for more than a day or two, there is a noticeable amount of scale that builds up in our equipment,” Lepe said. “Our baristas notice you right away.” Small water channels in machinery, such as those in steam lines, can stop working completely if the buildup becomes excessive. (The first evidence here is from a kitchen in London.)
Unless you are careful, filtered water can add significant time to the life of your coffee maker.
Don’t fall into this water trap
If your reaction to all of this is to fix it and use distilled water, really, don’t. “Filtering is better than nothing, but don’t use distilled water because your coffee will be very bad,” said Lepe.
The balance here is that you don’t want “pure” water with no minerals. “Water hardness is part of what’s going to make your coffee taste good, so you need other minerals in the coffee to help bring out the real flavor,” he says.
Fixing your water if it doesn’t work for you
Pod-style brewers without a built-in filter also benefit from filtered water.
So, how do you find the middle ground between demineralized water and demineralized water?
You can, of course, buy water to make coffee with, although that’s obviously not ideal. “I’m not advocating that people use bottled water, but there are certain types that are considered to taste better than others, based on the minerals,” Lepe said. “You don’t want a very strong mineral content, because it softens the taste; you want something in the middle,” he said, Crystal Geyser being a brand cited as a favorite by coffee connoisseurs. Before you invest in alternative water solutions, it’s worth doing a taste test with a barista-recommended bottled water product to see if you can tell the difference.
If you want to go full barista mode, though, some pros build a water profile from the ground up, using reverse-osmosis filter or distilled water, then add the minerals back. “There’s one book that I think has changed the way everyone thinks about water,” Lepe said, called Water for Coffee. “Now there are entire communities online that make traditional water recipes that mimic certain cities,” he said, “so, if you buy roasted coffee in Tokyo and you want to brew coffee to match it, you can find out what the water is like there, and they’ll give you recommendations on how to recreate it.”
This may seem extreme, but “it’s actually Epsom salts and baking soda that people add to water,” says Lepe. Brands like Third Wave Water and Lotus also offers quick, easy mineral packs to add to filtered or reverse osmosis water.
If you are not that committed, but still want to make the switch, a Brita water jug or a simple filter built into your faucet system is “a better place to start,” according to Lepa.
