How Does Water Quality Affect Coffee?

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You’ve splurged on high-quality coffee beans and own a state-of-the-art coffee maker. But your coffee still doesn’t taste quite right. What gives? The culprit could be your water. Don’t underestimate the impact of water quality on your brew.

This guide, backed by science, breaks down how factors like hardness, pH, impurities, and temperature can make or break your cup of joe. Here’s your roadmap to elevating your coffee experience.

Key Takeaways

  1. Optimal Water Hardness: A range of 50-175 ppm is advised, but recent studies narrow this down to 50-80 ppm for optimal flavor extraction.
  2. Balanced pH Level: A pH range between 6-8 aligns with scientific recommendations and offers a balanced setting for coffee extraction.
  3. Watch out for Impurities: Elements like chlorine and metals can severely deteriorate your coffee’s flavor.
  4. Temperature Control: Maintaining water temperature between 195-205°F is key for balanced flavor extraction.

Why Does Water Quality Matter When it comes to brewing coffee?

Many people consider water merely a brewing medium for coffee. They couldn’t be more wrong. Water is not just a solvent; it’s a vital ingredient that can either elevate or degrade your coffee experience. Let’s break down the science.

Water Hardness

Water hardness refers to the concentration of minerals, predominantly magnesium and calcium, in the water. These minerals have a direct impact on the extraction of flavors from coffee. The Specialty Coffee Association recommends a range of 50-175 ppm for optimal brewing.

The SCA suggests these specific qualities for coffee brewing water:

  • Clear and without odorless
  • Free from chlorine
  • Maintains a pH balance of 7.0
  • Contains an alkalinity measuring 40 ppm.

However, a specialized study from Coffee Next in collaboration with the University of South Wales1 suggests a more precise range of 50-80 ppm.

Comparison of Total Dissolved Solids (TDS) in Different Water Types

Water SourceTotal Dissolved Solids (TDS)
Spring Bottled62 ppm
Filtered Water23 ppm
Semi-Hardened Water140 ppm
Solid Hard water425 ppm

Water pH Level

The pH level of your water can make a tremendous difference. A balanced pH level between 6-8 not only assists in the flavor extraction but also compensates for coffee’s inherent acidity. A study conducted by Smithsonian Magazine2 supports these findings, emphasizing the impact of calcium ions and bicarbonate levels on coffee’s taste.

Impurities in Water

The presence of chlorine and metals in your water is like adding salt to a wound. They not only alter but can ruin the entire coffee experience. Impurities in water can lead to flat, metallic tastes, throwing off the delicate balance of flavors in your brew.

Water Temperature

Temperature plays a significant role in the extraction process. Water should be within a range of 195-205°F. Outside this range, you risk either under-extracting or over-extracting your coffee, both of which are detrimental to flavor.

My Own Real-World Insight

Drawing from my experience at Tully’s in Seattle, I witnessed first-hand how improved water quality can elevate the coffee experience. When the store finally changed its overdue water filters, there was an immediate and notable improvement in coffee quality. This was not an isolated observation; customer feedback aligned with this finding.

Further, a study from Ege University validated that water hardness significantly impacts coffee taste, reinforcing the value of quality water3.

Perfect Coffee with the Right Water: 5 Simple Steps

Want better coffee without the hassle? Here’s how your water can make a difference:

1. Choose Filtered or Bottled Water:

Tap water can contain stuff that affects taste. Switch to filtered or bottled water for a cleaner brew.

2. Check Water Hardness:

Using a simple test kit, aim for water that’s not too hard or too soft. Look for a label that says around 141 ppm if you’re buying bottled.

3. Keep an Eye on pH:

For the best taste, your water should be neutral, not too acidic or basic. If you’re curious, a pH between 6 and 8 is ideal.

4. Right Heat for Brewing:

Keep your water hot but not boiling, somewhere between 195-205°F. Most kettles or machines have a setting for this.

5. Clean Your Machine:

Just like dishes, coffee makers need a clean now and then. Regular cleaning helps keep that perfect taste.


Think of water quality as the invisible hand that shapes your coffee experience. You may have premium beans and top-notch brewing equipment, but if your water quality is off, your coffee will never reach its full potential.

The guidelines and practical recommendations outlined here are backed by science and real-world experience, ensuring that your next cup of coffee will be nothing short of extraordinary.


Avatar Of Kelsey Todd
With over two decades in the coffee industry, Kelsey is a seasoned professional barista with roots in Seattle and Santa Barbara. Accredited by The Coffee Association of America and a member of The Baristas Guild, he combines practical expertise with a profound understanding of coffee's history and cultural significance. Kelsey tries his best to balance family time with blogging time and fails miserably.