As we continue our post about the four coffee brewing basics we’ve already talked about the importance of getting good coffee beans. And we also talked about the importance of grinding those beans right before you brew your coffee. Now would like to talk a little bit about what makes the best water for brewing coffee. Coffee is 98% water. It stands to reason that having good water is a key part to brewing great coffee. But what makes up great water?

Water Hardness and Temperature

There are two components to water. The chemical makeup of the water (mostly related to water hardness) and the temperature of the water. We can dive very, very deep into all of the chemical components that make up your water. For you chemical engineers and uber geeks, we’re going to keep it very surface level here. Water hardness, on a very basic level, has to do with how many minerals are in your water. Depending on where you live and how you’re getting your water your water can be very hard for your water can be very soft. If you have hard water, you probably have a problem with lime buildup on your showerhead or around your sink faucet. In our area we see lots of the situation different situations depending on the city you live in and even which area of the city you live in.

Water hardness is measured in parts per million or grains per gallon. The best water for brewing coffee should have less than five grains per gallon in hardness or 50 parts per million. Water hardness test strips are accurate and very inexpensive.

As an example, the city of Geneva, where we are located, recently put in a state of the art water processing facility a couple of years ago. We’re very fortunate because the water here is only about five or six grains per gallon right out of the tap. Which is just about the best water for brewing coffee – maybe just a tad on the hard side but very usable.

On the other hand, some of our neighboring towns have older water processing systems and their water can be as hard as 24 or 25 grains per gallon. That’s just crazy hard. If you have well water on your properly you might be even higher than that. If your water is particularly hard, you probably already have a water softener in your home. Most water softeners at home use salt or another chemical to neutralize the hardness of the water. This is fine, however, you need to be aware that now you’re adding salt to your water, so you probably still need some kind of filter after the water softener in order to filter out any negative flavors that the softener adds to the water.

Beyond Water Hardness

Beyond the hardness of your water, you need to consider other chemicals, flavors and foreign tastes that are in your water. No matter how good your city tap water might be, they probably add chlorine and fluoride to the water. It’s almost always a part of city water treatment. Chlorine can wreck havoc with coffee brewing. If you don’t have any hardness problems, a simple charcoal filter can be used to filter out some of the chemicals and chlorine taste in your water. If you have a filter in your refrigerator water dispenser, make sure you change it regularly. If you don’t have a filter, consider using a Brita charcoal filter like this one.

Water can be Too Pure!

Don’t go overboard with your water. When we’re brewing coffee, we still need a certain amount of minerals in the water to help extract all of the coffee goodness from the beans. Reverse Osmosis (RO) systems typically create water that has almost no minerals in it and the result is weak coffee. Distilled water doesn't have the chemical and mineral components that allow us to taste flavors. It also can potentially do damage to certain coffee brewing equipment.

There are some solutions on the market to remineralize your water if you already have an RO system in place. Some include re-mixing some of the original un-softened water into the mix and others add a mineral mixture to the softened water to make it harder again. Both of these will definitely help you get the best water for brewing coffee if you have a system like this.

Water Temperature

Beyond using water that is filtered properly, brewing at the right temperature is very important to achieving the best water for brewing coffee. The Specialty Coffee Association of America (SCAA) tells us that the proper temperature for brewing coffee is between 195 and 205 degrees fahrenheit. For most purposes, we don’t need to get too fancy measuring water temperature. I use an electric kettle, bring my water to a boil, let it wait for 30 seconds and we’re right in that range. This is where most home coffee brewers fail. America’s Test Kitchen did a fantastic video about this (an older test they did is here). In their test, they found that from the low-end machines up to most of the most expensive machines, they all use the same 900 watt heating element. This heating element doesn’t get the water hot enough for most of the brew time. Sometimes, on some machines, the water was only 165 or 170 degrees. This is why coffee brewed in these machines is weak tasting. The colder the water, the less coffee awesomeness is extracted from the coffee grounds. In my own experience, I have customers that say they want “really dark roasted coffee”. When I explore things a little bit more, I usually find that they’re brewing their coffee with water that’s not hot enough. When you have “really dark coffee”, two things happen. First, even though you may not be getting good coffee flavor, at least you’re getting some kind of flavor. Secondly, the cellular structure of dark roast coffee is so weak from over-roasting that it falls apart as soon as almost anything comes in contact with it. So, you might not be extracting good coffee flavor from your beans, but at least you’re extracting something. I’ve found time and time again that when I properly brew even our lightest roast coffees for people using the absolute best water for brewing coffee, they describe it as “full”, “flavorful” and even “strong”.

How Can I Get the Best Water for Brewing Coffee?

Two simple steps moving forward getting the absolute best water for brewing coffee. First, if you’re not brewing with filtered water, start. Buy filtered water from the store, or get a simple charcoal pitcher like this one and start using it. If you’re more determined, have your water tested and consider adding an under counter filter or another more permanent solution to your setup.

Secondly, heat your water properly. An electric kettle is the fastest and easiest way to do that. It doesn’t have to be any thing fancy. I have a Black and Decker kettle at home that I picked up at Target. Make your pour overs, french presses, Aeropress or whatever coffee you’re brewing with water just off a boil. If you’re a drip coffee lover, consider an SCAA (Specialty Coffee Association of America) certified drip brewer like the Bonavita BV1900TS. One of the key points that the SCAA tests in their certification process is the temperature of the water. The Bonavita is a fantastic brewer that we can highly recommend.

We’re convinced that once you discover the difference using the best water for brewing coffee you’ll never go back. Stay tuned next week we’ll talk a little bit more about how to choose the right coffee brewing gear.