It’s been often repeated that coffee is 98% water. So it stands to reason that the water you use in brewing great coffee is very important.

But what makes “good” water? Excellent question. And, per usual, the SCAA has defined for us very clearly what good water is. In fact, you can download a PDF from their web site that explains in more detail than really any normal person should worry about, exactly what good water is.

The reality is, most of us aren’t about to have a water expert come by and test our water and install a complete water filtration and remineralization system in order to hit those water quality marks. What we really want is good coffee. To summarize it in two really simple points, your water needs to be 1) Filtered and 2) Hot. For the purpose of this post, we’re going to consider the first of these two items. The second is for another post (stay tuned!)

So what exactly is “Good” water?

Great question. There are lots of levels for “good” water. You can go from tap water to reverse osmosis purified water to distilled water and even cleaner. The fact of the matter is, for most coffee brewing, we don’t need perfectly clean water. Distilled water (water with EVERYTHING removed) will make your coffee taste even worse. We do want a certain amount of hardness and a certain amount of minerals in the water. This creates a pleasing taste and also helps to extract the oils and other components of the coffee bean that we want in our drink.

It’s not distilled water

First of all – distilled water is out. If you’ve ever tried to drink distilled water, you know that it technically is supposed to be tasteless. However, most people perceive distilled water as having a negative flavor because we’re so used to the taste of tap water and drinking water. On top of the fact that distilled water tastes bad, there are not enough minerals and other components in the water to help extract the oils and other components in the coffee that we want in our drink. Distilled water goes right through the cellular structure of the beans and extracts very little of the coffee.

Lastly, distilled water can do damage to certain coffee equipment. Since distilled water is completely lacking in mineral content, when it comes in contact with metal it tends to pull out the metalic components of whatever it is touching. In a coffee brewer, that can be the internal tubing or even an internal boiler or heater. Eventually, after running distilled water for a period of time, those metal components will become weakened and fall apart.

In addition to this, certain coffee equipment has sensors in the water tank and tubing that detects the presence of water. Some of those components and sensors use electrical current to do that. If you remember back to high school chemistry, distilled water does not conduct electricity. If you put distilled water in those coffee brewers, the brewer will likely not detect the presence of water and will show an error that there is no water in the tank.

Reverse Osmosis is probably Overkill

There are several products on the market that use reverse osmosis (RO) to purify water. There are 3, 4 5 and more stage systems that can fit under a counter or even be used to filter the water for your entire house. These are great if you’re on a well system that has really iron heavy water or if it has a strong sulfur smell to it, a RO system can definitely help you out. But you need to be cautious with coffee brewing because often times, RO systems take out too much of the mineral content and end up with water that is too soft.

If you don’t have an RO system right now and you’re on city water, hold off on buying a system until you get your water tested – or test the water yourself. You’ll save yourself a whole lot of time and expense.

Water Softeners are Questionable

Particularly the salt based water softeners. The way these work is by running the water through a brine tank that has what’s called a “resin bed” in it. That resin bed attracts the hard water minerals in the water and as the water is pumped out of the softener, the hard water minerals are left behind.

These water softeners can be a lifesaver in cities that have really hard water with a large mineral content. However, you need to be careful and keep your softener clean and regenerate the resin tank on a regular basis or it will stop working as well as it did when it was first installed. In addition, it can force a small amount of flavor in the water that may not be desirable in coffee.

The Good Stuff

According to the SCAA, if you’re brewing coffee, the perfect water is:

  • Clean, fresh and odor free
  • Clear in color
  • absolutely free from chlorine
  • 150mg/L total dissolved solids
  • 4 grains of calcium hardness
  • 40 mg/L Total Alkalinity
  • pH of 7.0 (perfectly neutral)
  • 10 mg/L sodium

That’s a pretty serious list! And personally, there’s no way I’m going to micro-manage my water system at home until it meets those standards. But what is important here is the fact that it needs to be clean and clear and free from that one biggie on there – chlorine.

Chlorine is an absolute killer when it comes to coffee. City water always has chlorine in it. Depending on what city you live in and how the rest of their filtration system is set up, you may have a little or you may have a lot. Most places in the US, you can really notice the chlorine in the system first thing in the morning (when you’re making your coffee!!). Lots of municipalities put the most chlorine in the system during the overnight hours because this is when it’s least noticeable to the average homeowner. However, when that water has been sitting in the pipes all night and you get up early and turn the water on, you’ll likely get a blast of chlorine odor coming from the water. It’s less noticeable at night because water has been running through the pipes most of the day.

The main thing that we should worry about when brewing coffee is getting rid of that chlorine and removing any other major odors, colors and tastes from the water.

How Do I Get There?

It’s actually pretty simple and, most likely, you already have the tools you need to make it happen.

Filtered Water

Some might go all home improvement and pull a “Tim Taylor” here. Actually, water filtration it’s a lot simpler than it sounds. The good news is you most likely don’t need a full 5 stage reverse osmosis water filtration system. Like we mentioned above, RO systems creates really REALLY clean water. So clean, in fact, that there are often not enough minerals  left in the water to extract all of the oils and other goodness in the coffee.

Brita Water PitcherBrita Water Pitcher


I would recommend that you start with a very inexpensive charcoal drip filter like the ones from Brita, that you can put in your refrigerator. With a system as simple as this, you’ll see an improvement in your water. The chlorine will be basically gone and anything that was affecting the taste or color of the water should be gone as well. These filters are easy to use and inexpensive to replace. Make sure when you purchase the water filter, you also pick up a couple of extra water filters along with it. change them often! Put a piece of scotch tape on the side of your pitcher with the date that it was last changed and change it every 3-4 months. Some of the filters have convoluted systems that try and automatically tell you when it’s time to change the filter. Don’t trust them! Trust the date and change the filters. You can’t go wrong by changing the filters too often and they’re relatively inexpensive.

Brita Pitcher Filters

Replacement Filters for the Brita Water Pitcher

An even easier option is a water filter that attaches directly to your sink faucet. However, I would issue the same caution with these filters that I did with the pitcher filter. Most of these add-ons have very small filters and they become saturated with whatever they’re filtering out very quickly. Make sure when you purchase it, you also purchase a couple of replacement filters and you change them ever 3-4 months at the outside.

Once you’ve determined that a charcoal water filter is enough for your setup, you can get a simple single stage filter at your local hardware store that should cost no more than $25-30. That can be installed under your sink and the faucet added to the sink to make it easy to get good, clean, filtered water.

If you find that there is still an offensive odor or taste to your water, it might be worth taking a trip to your local water professional and asking them what they would recommend. They are probably intimately familiar with the water in your area and can recommend a solution that will fit what you’re looking for. If you’re on a well system, it may be worth having your representative out to your location and testing the water. Most of the water treatment experts in most areas are willing to do this for you for no charge. You can also work with them to install the water system that’s perfect for your situation.

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