Water in Coffee: the Forgotten yet Essential Ingredient

Recently, my coffee brewing took a dive. I couldn’t figure out why, but all of a sudden, no matter what I tried I couldn’t get a good extraction. There was always a funny, muted taste in the cup.

So what was the problem? I realized that this ‘bad brewing’ period coincided with me moving to a new city. What I failed to remember is that, when we change location, we automatically change the ingredient that makes up over 95% of our coffee: the water.

As home baristas we spend lots of our hard earned dollars on coffee equipment and expensive coffee beans. We might have the best coffee brewing method possible, but if we are not factoring the type of water we use into our brew, we will never achieve proper extraction and we may as well be throwing our money away.

How the Minerals in Water Affect Your Coffee

While I was looking at a pour-over brewing method the other day, I was thinking about how rarely water is talked about when brewing coffee.

Hard water has a much higher mineral content than soft water. In general this is a good thing. There are more minerals present such as magnesium, which are essential for our health. However, high mineral content in our water supply is not beneficial for a good cup of coffee. Too many minerals can mute the flavors that we extract from the bean, resulting in a poor extraction. Therefore, perfect water for coffee brewing is soft.

Different Factors that Affect Water Hardness

The water you are using to make your coffee might have been influenced by a number of factors. For example, if you are living near the mountains, the water in your house is going to be hard. Water hardness will also be influenced depending on the water treatment system in your particular city, or the type of technology that they use.

Hard water from the mountains is bad for coffee brewing
Hard water from the mountains is bad for coffee brewing

How Do I Know if My Water is Hard or Soft?

The best and cheapest way of determining water hardness is by judging it for yourself. Pour yourself a glass of water and see how it tastes. More flavor means more minerals. If you can see white, chalky build up on your cooking appliances, your water is hard. You can also google the type of water in your locality. If none of these methods are working for you, or you have a private water supply, you can buy water testing kits to determine mineral content.

How to Adjust Water Mineral Content

The best way to easily extract minerals from your tap water is with water filtration. A standard, portable filter, such as a Brita filter, will remove many, but not all minerals from your water. If you make espresso coffee at home that plugs into the main water supply, you will need to install a more permanent filtration system in your house for optimum coffee extraction.

Can I Filter My Water Too Much?

Some mineral content is beneficial for coffee brewing. for this reason, more intense filtration systems that use reverse osmosis filtration are not optimal for coffee brewing. The same goes for purified and distilled water, which leave water completely devoid of mineral content.

Water filtering for better coffee
Manual carbon water filtering

Bottled Water for Coffee Brewing

Some specialty baristas use bottled water for coffee brewing. Specific mineral content is usually listed on the bottle label. This allows advanced baristas to develop a recipe for brewing with a specified mineral content. However, this is not an absolute necessity for the home coffee brewing and is a bit expensive.

Change your water, upgrade your coffee game

So if you are not brewing good coffee and you can’t figure out why, have a look at the water – it may just take your coffee to a completely new level.

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Josh Spink

Joshua is an Irish opera singer and writer. His specialist topics are coffee, food, wellness and culture. His love for coffee comes from growing up in his parent’s coffee shop and working as a barista for several years in the specialty coffee scene in Dublin. As an opera singer, Joshua is a frequent traveller and is passionate about discovering new coffee shops in every new place he visits. Joshua is fascinated by the health benefits of coffee drinking and is an advocate of moderate coffee consumption as part of a healthy lifestyle. Apart from drinking and writing about coffee, Joshua enjoys cooking, all forms of exercise, reading and languages.