Essentials to making great coffee at home (Part Two - Water)

February 01, 2019

What about my water important for great coffee?

(Part one of this three part series discussed the importance of quality coffee. Click here to read it.)

Quality water is essential to great coffee.

You may be thinking:

Seriously? Water is water is water, right? And the water I have is what I have.”

Chances are, your water is fine as it is. But remember that coffee is mostly water, so it will impact the taste of your coffee. Here are the big considerations when it comes to water, and what you should do if any of them apply.

water faucet

Avoid odorous or chlorinated water.

If your water has a specific odor or tastes of chlorine (or any other distinctively bad flavor), the taste will show up in your coffee. And you probably won’t like it.

When I was a kid, we would drive up from Atlanta to visit family outside of Knoxville. There was an area we would drive through called “Sweetwater.” It was anything but. The air reeked of sulfur. If you haven’t smelled sulfur before, it’s pungent. The water in the area smells and tastes of like eggs boiled for hours. You would not want to use it in your coffee.

What do you do if you have odorous water? First, try using some sort of filter on your tap water. If the unpleasant taste still lingers, use store-bought “drinking” or “spring” water for coffee brewing. Don’t use distilled water; the water needs some mineral content for proper extraction.

The "Goldilocks" of mineral content.

Remember the story of Goldilocks and the Three Bears? She always looked for the bowl of porridge or the bed that was "just right."

Mineral content for coffee brewing is similar: coffee brewing requires some mineral content in the water, but too much or too little may prevent a proper brew. This is because mineral content and water hardness affect solubility. Solubility refers to the amount of solid that dissolves in a liquid, in this case, crushed coffee beans in water. So the water matters.

Most people are familiar with the terms "hard water" and "soft water." Hard water describes water with a high amount of dissolved calcium carbonate (CaCO3), also known as limestone or chalk. Soft water describes water with a lower amounts of CaCO3. At the extremes, people may "soften" hard water by removing minerals, or "harden" soft water by adding minerals, all to get the water "just right." The amounts of types of minerals present in the local water supply vary by jurisdiction.

If you suspect the mineral content of your water isn't "just right," try filtering or buy “drinking” or “spring” water. If you have money to burn, companies exist that will sell you water especially formulated for coffee brewing.

If this is all too imprecise for you, ask your water department for a report detailing the city's water profile. Compare that information to published standards of “ideal” coffee water.  Don't be afraid to ask: We got our water profile when we brewed beer and the people are super nice and helpful. Or, you can buy a water testing kit to measure the amount of minerals in your water. Armed with that information, you can determine whether your water is suitable for making great coffee.

One final note: don’t use distilled or reverse-osmosis water to make coffee. It lacks the necessary minerals for proper extraction.

TL;DR: Quality water is essential to great coffee. Quality water is odorless, free of chlorine and bad tastes, and has a mineral content that is “just right.” You can buy, filter, or adjust the content of your water if your tap water is problematic.

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