Why Does Coffee Water Matter?

A cup of brew is typically made up of two elements, the actual coffee itself, and water (and milk and sugar sometimes which is okay too!). We put so much focus on the coffee, but what about the part that makes up 98% of the brew? Let’s dive into the water!

Hard Water vs. Soft Water

We’ve all heard these terms before, but how do they pertain to coffee? Hard water is the excessive presence of calcium and magnesium- two naturally occurring minerals in water. The more calcium and magnesium, the harder the water. Conversely, soft water is defined by the absence of these minerals and is typically created through some type of filtration system.

Water hardness or softness depends on where you live, Toronto’s water hardness resides at around 130 milligrams per litre, whereas Vancouver’s hovers around 9 mg/l. The levels of hard water aren’t region-specific and are largely due to the area’s water source. For example, in Canada you can find the hardest water in Winnipeg, Regina and even Cambridge, Ontario at around 400 mg/l. This can be attributed to the presence of limestone in local water sources or through the use of ground wells.

Whether water is soft or hard makes no difference from a health stance and causes no negative side effects (though harder water may contribute to dry skin and hair). However, it does present a risk to the condition of brewing equipment and can affect the taste as well.

We can explain this better using the metaphor of salt:

Minerals in coffee water function similarly to salt in cooking; without adding salt to a meal, your food can end up on the bland side. Similarly, too much salt is bad for your health, just like water with too much mineral content can be bad for your brewing equipment, causing crusty white buildup known as scale. The goal is to find the right mineral content in water that works well with the coffee but won’t cause scale on your equipment.

The Optimal Water

The Speciality Coffee Association of America found that the ideal mineral balance is 150mg/l, and found that coffee brewed with this level of hardness is more balanced and smooth. For those of us living in Toronto, this is great news! For readers who live in soft water regions, skip ahead a few paragraphs, we got you covered too.

Using Tap Water For Coffee

If you’re lucky enough to live in an area with optimal water hardness, tap water might be the easiest solution for your perfect brew. Just remember to always use cold tap water. It might seem like the logical first step to fill your kettle with warm or hot water since you are trying to achieve that perfect 96 degrees, but hot tap water tends to have lower oxygen levels which can affect the taste. Cold tap water is fresher, coming straight from the supply source, whereas hot water tends to reside for longer periods of time in hot water tanks.

Using Filtered Water For Coffee

If you use a Brita filter or a charcoal filter, it doesn’t alter the hardness or softness of your water. These filters use carbon cartridges to improve taste and remove any heavy metals present in the water, but they do not remove dissolved salts such as calcium or magnesium.

Reverse Osmosis or Distilled

It seems like it would make sense to use the purest water when brewing coffee, but in reality, water that is too pure such as reverse osmosis or distilled is lacking in minerals. These methods take out all impurities, the good and the bad, and using this water in coffee could make your brew taste over-extracted and bitter.

What If My Water’s Too Soft?

If you live in a soft-water region, or use reverse osmosis/distilled H2O don’t fret, because there’s help!

Companies like Perfect Coffee Water are here to save the day! Their mission is simple, to provide you with - as the name says - the perfect coffee water, regardless of location.

“Here’s a solution for you to really extend that cafe experience to the person at home,” explains Courtland King, one of the brothers behind Perfect Coffee Water, “it’s just a way to get that same consistency and standardization. Like, if you’re paying $25 for a bag of coffee, let’s get it dialed with the water for you.”

Perfect Coffee Water retails for only $7.50 and creates 30 cups of coffee, with water tailored to bring out the best in your brew.

How Does Coffee Water Make a Difference?

We’ve gone through the best types of water for coffee, but what about the end result?

“There’s greater clarity in the cup, so you’re tasting the coffee for how it should be tasted,” King explains, “It’s juicier, we get that often. Better body and mouthfeel in the coffee.”

The reason for this? Hard water with higher levels of magnesium will likely extract more flavour in coffee, as the compounds tend to attach themselves to the flavourful elements in roasted coffee beans.

King puts it best: “Coffee is this interesting thing where you have so many thousands of hours going into countries of origin, the roaster puts in hundred or thousands of hours into their roast profiles, then it gets sent home with the consumer but it’s not a finished product yet, it still has to be brewed by them. A huge thing that’s affecting the taste of that brew is the water. And so, by putting a little more focus on the water, you can ensure that your $25 bag of coffee is going to hold up all the way to your cup once it’s brewed.”