The Importance of Water Quality in Coffee Preparation

Did you know 98% of your cup of coffee is water?
Posted on August 19th 2015 by Maddie

“The art of coffee brewing is in controlling the variables; and water quality must be controlled, and held in balance, in order to achieve a flavorful beverage.”

David Beeman and Paul Songer, the Water Quality Handbook

Did you know 98% of your cup of coffee is water? Subsequently, the quality of your coffee is directly linked to the water used to brew it. Not all water is equal. Water varies by location, even within the same city.

H₂O Fundamentals

Pure water is a simple combination of two gases: hydrogen and oxygen.

Two hydrogen molecules and one oxygen.

Water will take on different physical forms when temperature is increased (steam) or decreased (ice).

It is hard to imagine that such a simplistic formula is actually one of the most important variables in the preparation of coffee.

You will rarely find water in its pure form. Safe drinking water will typically contain dissolved substances, mineral content and additives. All which ultimately influence our coffee cup. With brewed coffee, it is desirable to have some mineral content (hardness) in your water. Soft water is ideal for brewing espresso.

Dissolved Solids

If some chemical compounds are present and found with relatively large amounts in water, they cause unusual tastes, odors, and colours. On a molecular level, they are structurally part of the water so they are referred to as dissolved solids.

This is where methods of filtration are necessary to separate them. Municipalities are responsible for treating our water to make it safe for human consumption. Varying treatment methods ultimately affect the water from your tap.

Location Matters

Water quality varies by location. In Canada, we often take for granted the quality of our available water. Our water must meet specific safety standards for consumption.

Health Canada has worked with our provincial and territorial governments in establishing guidelines that set out the maximum acceptable concentrations allowed in our drinking water. The ultimate vision is that every water system should provide the cleanest, safest and most reliable drinking water possible. 

Water’s Impact on Extraction

The mineral balance in water can influence coffee’s extraction as it reacts chemically and physically with ground coffee.

The composition of water can lead to over or under extraction.

For example, an unbalanced, salty, bitter tasting coffee can result from increased chloride from increasing salt-water in the water supply.

Alternatively, an alkaline taste, (dry and chalky cup) can be attributed to arid geographical areas with a high number of minerals.

Specialty Coffee Association of America’s Water Standards for Coffee Brewing

The Specialty Coffee Association of America (SCAA) has created high standards required for proper extraction. The SCAA’s Golden Cup Standard is a certification of high quality, freshly brewed coffee. The water used for brewing has its own strict guidelines. 

The first two water standards for coffee brewing seem obvious. Water should be odor and colour free, same goes with Chlorine. Next there are acceptable ranges for each of the following:

  • Total dissolved solids
  • Calcium hardness
  • Total alkalinity
  • pH
  • Sodium content

Find out all the specifics here.

Maintenance of Brewing Equipment

Not only is water important for taste, but it also contributes to maintenance of brewing equipment.

Adherence to water quality standards not only improves beverage quality, but it also reduces the need for brewing and espresso equipment maintenance, thereby eliminating down time and frequent equipment repairs, resulting in a cost savings for café owners.

Coffee Dehydrates

Since we are already talking about water, I thought we might as well clear up a common misconception of coffee’s effect on the body.

Is coffee a diuretic? Does it cause dehydration?

Caffeine does have diuretic components. However, if your coffee consumption is about two cups of coffee daily – which you will be happy to know is considered normal – you will have developed a tolerance. Those who do not consume coffee often seem to be the ones that will notice a pronounced diuretic effect.

Researchers at the University of Birmingham recently completed a study which compares the effects of coffee consumption against water ingestion. Conclusions suggest that coffee when consumed in moderation by regular drinkers provides similar hydrating qualities to water.

"It's well understood that if you drink coffee habitually you can develop a tolerance to the potential diuretic effects of coffee," says study author Sophie Killer, a doctoral researcher at Birmingham.

Another lesson in moderation for sure. Not to mention the importance of quality water, a key aspect to brewing and enjoying a Kick Ass® cup.