The Best Water for Making Coffee Explained

Imagine this: After realizing you’ve been latte-ing away your money at your favorite coffee shop, you decide to start brewing your coffee at home. Of course, you want the same quality coffee you’ve become accustomed to, so you purchase an expensive coffee maker and some high-class coffee beans.

You weigh the beans to the gram, adjust the grind, heat the water to the ideal temperature, and use the right filter. You do almost everything you can to make the best-tasting coffee possible. But after taking your first sip, you sprint to the sink to spit it out. As you pour the remaining coffee down the drain, you can’t help but wonder why your coffee still tastes like crap, though you did everything correctly (or so you thought).

As simple as it sounds, the answer might be the water you are using to brew your coffee. Unless you are a serious coffee lover, you might not be picky about the water you use to make your morning cup. But when you consider that a cup of coffee contains over 98 percent water, you shouldn’t be surprised that crappy water gives you crappy coffee.

So, what’s the answer then? How do you make the same mind-blowing coffee that’s available at coffee shops, cafes, etc.? Before we spill the beans (saw what we did there?), let’s discuss why water quality matters so much when brewing coffee and break down why unfiltered tap water is terrible for coffee brewing. Then, because we want to help you make nothing but delicious and flavorful coffee, we’ll explain an easy and inexpensive way to get filtered water at home.

Why does water quality matter so much when brewing coffee?

Think about what goes in a cup of black coffee: the grounded coffee beans and water. Even though the beans you use will decide the flavor, the water you brew with can make or break your coffee.

Most people consider the quality and freshness of the coffee beans, grind size, water-to-coffee ratio, contact time, water temperature, and brewing method as the most important factors when making a delightful cup of coffee. However, choosing the right water and ensuring its quality is equally important. By quality, we mean the water should not negatively affect the taste, aroma, or any other attributes that define a great cup of coffee.

Furthermore, water is the most abundant ingredient in a coffee brew, making up around 98.75 percent of the beverage. With this in mind, it should be evident that your water’s chemistry will leave a marked impact on the appearance, smell, and taste of your coffee. Hence, paying attention to your water quality is crucial.

What’s the deal with unfiltered tap water in coffee?

For most people, using tap water to brew coffee is a no-brainer. Sure, it is easily accessible across the country, but it has a huge downside when it comes to brewing coffee: it might hurt the quality of your coffee (unless it’s filtered, of course).

Depending on where you live, the tap water flowing through your home might come from a municipality, a nearby river or lake, or from a groundwater well. These different sources mean that your tap water quality and taste will likely differ from one region to the next. For instance, agricultural areas in the US generally have tap water with high levels of nitrate runoff. In the western regions, tap water often tastes saltier since these areas rely on brackish (salty) groundwater as a crucial drinking water source.

But no matter your location, there’s a chance that your tap water contains traces of various minerals, chemicals, gases, heavy metals, and other unwanted elements – the amounts of each depending on where you live and your water source. For this reason, you can brew the same coffee with different water types and get different flavors each time, which explains why coffee brewed with water at your local coffee shop tastes different compared to brews made using tap water at home.

The main concern with using unfiltered water to brew coffee is that it adds considerable amounts of unwanted chemical contaminants and other elements to your coffee, resulting in weaker and less appealing brews. Chemicals like chlorine and chloramine can taint the coffee with a pungent chemical smell and aftertaste. Also, heavy metals, such as aluminum, manganese, and copper, among many others, can impart a slightly acidic or metallic taste to your tap water. This sour or metallic taste may then carry over to your coffee when you use unfiltered tap water to brew your coffee. Unfiltered water is also known to cause other problems like water hardness, which is often responsible for highlighting the coffee’s bitter notes.

For the full taste, body, and smell of the coffee to emerge, the water you use must be free from odor, color, and chlorine. Otherwise, even the highest-quality coffee beans and a tried-and-true brewing method may yield some of the worst coffee you’ve ever tasted.

Still, if you are content with the coffee you make using your tap water, and you have consistent results, you can use that water. But if you find that the taste of your coffee changes a lot from day to day, even when you’re using the same brands of beans and the same recipe, we recommending filtering your water.

Is it safe to use unfiltered tap water to make coffee?

Using unfiltered tap water for your coffee is unsafe. Not only does it increase the risk of stale and boring coffee, but it may contain harmful contaminants picked up as the water traveled to your home. Bacteria, heavy metals, chemicals, and other unwanted matter may have leached into the water from corroding pipes, through water main breaks, etc. And guess where these elements and compounds will likely end up? Right in your coffee cup. So, unless the water is treated again at your home with a reliable water filter, we don’t recommend using unfiltered tap water for coffee.

What needs to be removed from the water for brewing coffee?

There are quite a few unwanted elements commonly found in water that can affect the color and odor of water, and later, the coffee’s distinctive and inviting flavor and aroma. To preserve that irresistible taste and smell, all water used to brew coffee should be completely colorless and odorless.

Here’s are a few pollutants known for cloudiness, discoloration, tinting, and bad odor in water:

  • Chlorine: Chlorine, a chemical widely used to disinfect water supplies, is notorious for imparting a strong pool water-smell on water. Any detectable chemical level will tarnish the coffee’s flavor profile with a harsh aftertaste and prevent the coffee beans’ unique flavor notes from translating onto the palette.
  • Phenol compounds and bacteria: Phenol compounds can leave a medicinal odor, whereas bacterial presence can cause the water to smell like decay.
  • Hydrogen sulfide: Hydrogen sulfide can taint the water with a pungent, rotten egg odor.
  • Heavy metals: Red or orange coloration of water often indicates heavy metals, like iron, copper, or rust particles, in the water. These metals can leach into water from aging, corroded pipes and are prevalent in groundwater supplies. While low concentrations of specific heavy metals aren’t a serious health threat, they can leave a metallic taste in the water and ruin the brew’s color.
  • Dirt and debris: Sediment, dirt, debris, sand, silt, and other particulate matter are extremely undesirable in water used to brew coffee. These elements not only impair the color of the water but could leave your coffee with a dirty or gritty taste.

Why Filtered Water is the Best Water for Brewing Coffee

International baristas swear by filtered water for being the best water for coffee making. In addition to making great-tasting coffee, filtered water also prevents limescale buildup in coffee makers and automatic coffee machines, averting damage to the devices and, therefore, reducing repair costs and frustration. But most importantly, filtered water usually contains enough minerals to enhance the coffee’s taste – an important part of the coffee-making process.

Based on the SCA’s (Specialty Coffee Association) widely used water-quality standards, a superior quality coffee extraction requires water with the following characteristics:

Characteristic Target Acceptable Range
Odor Odor-free, clean, fresh
Color Clear
Chlorine None None
Alkalinity 40 ppm At or near 40 – 70 ppm CaCO3
Calcium Hardness 50 – 175 ppm CaCO3 50 – 175 ppm CaCO3
pH 7.0 6.0 – 8.0


Luckily, a water filtration system can produce water within these parameters while retaining essential minerals for exceptional flavor extraction and full-bodied taste and aroma.

A water filter system does an excellent job of reducing impurities, odors, unwanted minerals, chemicals, and other quality-impairing contaminants from your water. As a result, the water going into your coffee is cleaner and better-tasting, which is crucial for brewing coffee that tastes and smells great. A water filtration system can also reduce scale-buildup in your coffee maker, which could otherwise damage the appliance.

How does hard or soft water affect the flavor of coffee?

When it comes to water for coffee, there is more than just filtered and unfiltered, or salt or freshwater. We also have hard water and soft water.

Tap water in different areas could contain a diverse mix of minerals, such as magnesium and calcium, which will determine whether it is hard (high in minerals like calcium and magnesium) or soft (low in mineral content). When coffee, which contains a ton of natural chemicals and aromatic compounds, mixes with hard or soft water, the results can vary tremendously.

Water hardness is determined by the amount of calcium and magnesium dissolved in the water. Now, both minerals are very coffee-friendly. These minerals are “sticky” and will latch onto certain compounds in the coffee grounds, drawing out flavor from certain roasts for enhanced taste and stronger or more caffeinated brews.

On the other hand, soft water contains less calcium and magnesium but is higher in sodium. Therefore, soft water won’t extract as much flavor as hard water, which may cause your coffee to taste flat. But that doesn’t mean hard water extracts good flavor, and soft water doesn’t. Bear in mind that not all hard water is created equal. Hence, living in an area with hard water doesn’t guarantee a better cup. It all depends on the water’s chemical makeup and how it will interact with your coffee beans.

So, do we use hard or soft water in our coffee? Unfortunately, the answer to this question isn’t one-sided. Instead of choosing hard or soft, it’s about finding the right balance that you enjoy when sipping your morning coffee.

If your water is too soft, the coffee may taste less flavorful and have a salty aftertaste. And if your water is too hard, you may deal with more bitterness and a host of household and grooming problems. Heck, hard water can even cause mineral buildup in your coffee maker and ruin it over time, making each cup taste a little less amazing. Therefore, we recommend choosing the right balance based on your preferred taste.

What about distilled water, reverse osmosis (RO) water, or even bottled water?

So, hard water seems alright, but it has problems. Soft water is a bad idea. Can you make coffee with distilled water, RO water, or even bottled water, then?

There is an ongoing debate about whether distilled water is good for coffee, but the truth is that distilled water lacks the minerals that give coffee its delicious taste. That’s right, the same minerals filtered out of distilled water in bulk are needed in smaller amounts to get that superior coffee taste. But distilled water can be an important step toward getting the best water for your coffee.

RO water is somewhat similar to distilled water. Both types of water have been cleaned thoroughly, leaving them nearly void of anything but good-ole H2O. The difference with RO water is that some RO systems have remineralization capabilities. The remineralization post-filter passes the water through alkaline-rich media, raising both the alkalinity and the water’s pH. This protects the water from being too acidic for proper brewing and reintroduces some of those coffee-friendly mineral content back into the water. As for bottled water, we don’t recommend it for various reasons.

How to Evaluate your Water Source

If your tap water tastes or smells funny, perhaps having a rotten egg scent or chlorine odor, you might want to evaluate your water source to determine the cause before using it to brew your morning coffee.

Here are a few ways to evaluate your water source:

1.     Locate your city’s latest water quality report.

For the safety of residents, US cities must share information about their water quality publicly. Therefore, you can look up everything you want to know about the tap water in your area. You can do a quick Google search for your town, plus the phrase “Water Report.” For instance, “Tampa Bay Water Report.” Look for your city’s latest report and see what water quality information you can find. Alternatively, you can contact your local water provider and request a copy of the document. However, before obtaining the water quality report, it’s good to know how to interpret its content. Thankfully, our article, How to Read Your Water Quality Report: Helpful Tips and Expert Advice, will help you do just that.

2.   Evaluate your water quality with a home water test kit.

If you want to play mad scientist for a few minutes, order a water testing kit and discover more about what’s really in your tap water. These kits are available from pool companies, pet stores, and also online from various merchants. Water testing kits are relatively cheap and can produce accurate results in a relatively short time.

3.   Send a water sample to a certified local laboratory.

For more thorough testing and accurate results, send a water sample from your home to a certified lab in your area. Although laboratory testing can be more expensive and time-consuming than the other methods described above, it is usually the most accurate. Once you compile your water quality information, compare your results to the SCA standards (see the table above). Does your water source fall within the acceptable range?

So, what’s the best water filtration system for your coffee at home?

When it comes to ruining the taste of coffee, chlorine is the biggest offender. Not only does the chemical disinfectant suppress the natural aromatics of coffee, but its unpleasant bleach scent may mask the robust, full-bodied smell of freshly brewed coffee. Chlorine will also subdue the coffee’s tasting notes, preventing the natural tones from landing on your palette. Luckily, water filters, like the Springwell CF1 whole-house filtration system, are excellent for removing chlorine and other pollutants from water, thus improving its overall taste and quality.

The CF1, in particular, removes organic pollutants like VOCs (volatile organic compounds) and trihalomethanes and is designed to reduce contaminants like lead, asbestos, cysts, copper, PFAS, pesticides, herbicides, haloacetic acids, and many more. The system is made with environmentally-friendly charred coconut shells designed to remove organic contaminants. It also uses KDF media to remove specific pollutants and a 5-micron sediment filter to eliminate dust, dirt, sand, silt, debris, and other particulate matter. What’s also great bout the CF1 is that it retains essential minerals that give coffee its distinct flavor. But that’s not all.

When you purchase the CF1 directly from our factory, you get over 50 percent more savings than when you buy it elsewhere. Also, the system comes with a lifetime warranty, a six-month money-back guarantee, and free shipping. And most importantly, you get the peace of mind knowing you have a filter in your home that will significantly enhance your hot or cold coffee brews and get your homebrew coffee routine on track.

Check out this article to learn more about the Springwell CF1 and why it is the best water filtration system for homes connected to municipal water supplies. If your water comes from a private well, this post explains why our WS1 whole-house well system is the best for families who get their water from private wells.

Final Thoughts

Brewing coffee at home can be a fun experience. It can be a great addition to your morning routine and may help break up the humdrum of the day. But as we’ve discussed in this article, every great batch of coffee brew starts with good water. After all, coffee is 98 percent H2O. We agree that the chemistry behind water may not be that interesting for some people, but it’s an essential component of the coffee brewing process. With that in mind, please make sure to filter your water before using it to brew your morning cup. Your taste buds will thank you!