Does Water Quality Matter for Coffee? What Businesses and Baristas Need to Know
Does Water Quality Matter for Coffee? What Businesses and Baristas Need to Know
Did you know that the average cup of coffee contains approximately 98% water? For espresso, that number is around 90%. Besides the beans, grind, temperature and brewing method, water quality plays a crucial role in making high-quality, good-tasting coffee.
Poor water quality can wreak havoc on espresso and coffee machines, degrading performance and negatively impacting taste — especially for coffee shops that see a high volume of daily use. In this article, we’ll explore how water affects coffee and the best water filtration methods for brewing the perfect cup.
Why Water Quality Is Essential in Coffee Brewing
Different types of water influence the flavor quality extracted from your coffee beans. This is because the water undergoes chemical reactions with both the beans and the internal components of the machine during the brewing process.
Water that is too hard, too soft or contains impurities such as chlorine can make the coffee taste too bitter, sour or even metallic.
Impurities
Chlorine and other disinfection chemicals are added to municipal water as part of the treatment process, though they are not ingredients you want in your latte. Disinfection chemicals and their byproducts can cause a chemical, metallic or bitter taste in brewed coffee.
City water left unfiltered can also contain impurities such as sediment, PFAS forever chemicals, iron, copper and sulfur bacteria, all of which can interfere with the coffee’s natural flavors.
Hard vs. Soft Water (Mineral Content)
Standard tap water in the US is often hard, meaning that it contains a high concentration of minerals like magnesium and calcium. While these minerals play a crucial role in bringing out flavor in brewed coffee, in excess they mask desirable notes in the coffee and contribute to over-extraction, resulting in a bitter, dull or harsh taste.
Too many hard water minerals also cause scale buildup in espresso and coffee machines. Scaling reduces the machine’s lifespan and efficiency over time, putting a costly strain on pumps and heating elements, reducing water flow rate and causing inconsistent water temperatures and uneven extraction.
Water with a low mineral content also hurts the coffee’s taste, which is why it’s best to avoid distilled or purified water (unless you’re adding minerals back in). The lack of calcium and magnesium results in under-extracted coffee that tastes sour, overly acidic, weak and lacking complexity.
Keep your water at the optimal levels of hardness to help make a balanced cup of coffee that emphasizes the bean’s natural flavor profile. Recommendations for water hardness, according to the Specialty Coffee Association (SCA):
| Calcium | 10 – 50 parts per million (ppm) |
| Magnesium | 3- 20 ppm |
| Total Hardness | 50 – 175 ppm as CaCO₃ |
pH Levels
Water pH refers to the measure of acidity or alkalinity on a scale of 0 to 14. A neutral (7.0) to slightly alkaline pH is considered ideal for brewing coffee.
A pH that’s too low (below 6.5) is acidic and can cause a sour flavor and corrode the machine’s internal components. Water with a pH of 8.0 or higher can contribute to a flat, bitter taste, dulling the coffee’s natural acidity and increasing scale buildup in the machine. The SCA’s recommended sweet spot for pH is between 6.5 and 7.5.
Alkalinity and Bicarbonates
When it comes to your coffee’s flavor, alkalinity plays a stronger role than pH alone. (pH, however, still impacts taste and especially equipment health.)
Alkalinity, in a nutshell, is how well water can buffer or resist changes in pH. The presence of bicarbonates (HCO₃⁻) in water, which are naturally occurring dissolved mineral compounds, helps to neutralize acids and keep water from becoming too acidic.
The SCA recommends using water with bicarbonate (alkalinity) levels of 40 – 75 ppm (as HCO₃⁻). The result is a lively, flavorful cup of joe with balanced acidity, sweetness and complexity, with the bicarbonate neutralizing unpleasant bitterness.
If your water has too few bicarbonates, your coffee can taste sour. Too many, and the flavor becomes flat and chalky.
Total Dissolved Solids
Total dissolved solids (TDS) is the concentration of all minerals, trace metals, salts and other organic substances dissolved in your water. High TDS (over 250 ppm) can interfere with coffee’s extraction and result in a muddy or heavy taste, due to the overabundance of minerals and solids. A higher level of TDS also correlates with scale buildup.
TDS that’s too low (under 50 ppm) can cause under-extracted coffee that tastes weak, sour or empty. The impact on espresso and coffee machines isn’t as bad, though if alkalinity is also low, this can lead to internal corrosion.
According to the SCA, 75 – 250 ppm is the ideal range for TDS. Below is a helpful chart showing the SCA’s water quality standards for making coffee:
Purified Water vs. Tap Water: What’s Best for Coffee?
Tap water, in general, includes a high concentration of hardness minerals, chlorine, iron, sediment, disinfection chemical byproducts, forever chemicals, trace metals: the list goes on. All of these impurities are best left out of your cup of coffee and coffee machine.
Purified water provides a consistent taste and can significantly reduce unwanted contaminants, including total dissolved solids, chemicals, sediment and minerals.
However, an RO system on its own may remove too much of the magnesium and calcium needed to create a delicious, balanced cup of coffee. Restaurant and coffee shop owners may benefit from installing a combination filtration and RO system that removes impurities and enriches water with the necessary amounts of magnesium and calcium.
Pinpoint the system you need with a water test that identifies contaminants and water problems, such as low pH.
Do Coffee Shops Use Filtered Water?
Many cafés, restaurants, bars, hotels and even offices use water treatment to deliver top-quality drinks to patrons. Commercial-grade water systems are capable of meeting high demands for contaminant removal while improving operational efficiency. Commercial water treatment systems tend to have high flow rates, high daily capacities (from 500 to over 1,000 gallons per day) and an energy-efficient, durable construction.
How Businesses Can Improve Water for a Better Coffee Experience
Water testing and water treatment are the two main steps to improving the water that goes into your coffee. Keep in mind factors such as the water’s mineral balance, hardness, pH level, as well as the cost impact on your business. Besides the system itself, look for long filter lifespans and eco-friendly, low-maintenance equipment. Some water treatment companies, such as Kinetico, also provide a free post-installation appointment and automatically scheduled system maintenance for minimal interruptions to your day.
Investing in a quality-built water system can save your business significant costs over time. Owners can provide better-tasting, healthier coffee products while reducing wear and tear on water-using equipment and reducing waste.
Use a Filtration & Purification System
Filtration and reverse osmosis (RO) purification are both excellent choices for anyone looking to improve their water quality and the taste of their coffee.
At Kinetico, we offer state-of-the-art, non-electric water systems designed specifically for coffee making that can be tailored to the desired levels of minerals and TDS. This helps coffee shops have not only the best beans but also the best water to make the best cup of coffee possible. In a country with over 40,000 coffee shops, taste is what matters most.
Test Your Water
Everyone’s water is unique. Testing your water is the only way to know what’s in it and to get the right treatment for all your water needs. The makeup of your water and its contaminant levels can vary significantly depending on its source, such as well versus municipal water.
For best results, schedule a water test with certified professionals who will test for a wide range of contaminants and impurities, from hardness minerals to iron and manganese, acidity (pH), TDS, sediment and more.
Experience the Kinetico Difference in Every Cup of Coffee
Customers across the country trust Kinetico to improve their business through sound, science-based water treatment and world-class customer service. Book your free, no-obligation water test with Kinetico today, backed by industry-leading equipment and over 35 years of experience.