Coffee is made up of approximately 98% water, so water quality is one of the most important factors affecting the taste of coffee.
For professionals, understanding water quality is crucial to making great coffee – whether at home, in a café or in an office environment.
This article discusses why water quality is important, what factors to consider, and how you can optimize water use in coffee making.
Why is water quality important in coffee making?
Coffee extraction is a precise process where water acts as a solvent and extracts the coffee aromas, flavors and oils from the ground beans. The mineral content, purity and chemical properties of the water affect what flavors the water can extract. Poor water quality can mask the nuances of the coffee and result in a bitter or tasteless result.
The most important water properties for coffee making
1. Clean and neutral taste
The taste of your coffee may suffer if the water contains impurities such as chlorine, metals or other strong flavours. Use water that is neutral in taste and clean.
2. Mineral content (hardness)
The mineral content affects how well water can extract coffee aromas.
• Light mineral content: Improves coffee flavor and balances acidity.
• Water that is too hard: Can cause a bitter taste and leave limescale deposits in coffee machines.
• Water that is too soft: Cannot extract enough flavor from the coffee, which can make the end result weak.
The ideal mineral content for coffee is 75–150 ppm (mg/l).
3. PH level
Neutral or slightly acidic water (pH 6.5–8.0) is best for brewing coffee. Water that is too acidic can accentuate the bitterness of the coffee, while water that is too alkaline will make it unbalanced.
The effect of water on the taste of coffee
1. Water that is too hard:
• High mineral content, such as calcium and magnesium, can make coffee bitter and unpleasant to taste.
• Can also cause limescale buildup in the coffee machine, which reduces the machine's performance.
2. Water that is too soft:
• Water with very low mineral content does not support adequate extraction of aromas and flavors. The end result can be a tasteless or “latte” coffee.
3. Impurities:
• Chlorine, sulfur, or metals in the water can mask the natural aromas of coffee and leave an unpleasant aftertaste.
How to optimize water quality for coffee making?
1. Use a water filter
• To remove chlorine and impurities, we recommend carbon filters or other household filters that improve water purity.
2. Monitor water hardness
• In professional use, it is advisable to measure water hardness using, for example, test strips or digital meters. Water quality can vary even within the same city.
3. Descaling coffee machines
• If you use hard water, make sure to descale your coffee machine regularly. This will improve both the taste of your coffee and the performance of the machine.
Examples of practical effects
Espresso:
With water that is too soft, espresso can easily become watery and lack full body. With hard water, espresso can be bitter and unbalanced.
Pour over:
Refined flavor nuances, such as fruitiness or florality, are best emphasized when using lightly mineralized water.
Cold Brew:
The long brewing time emphasizes the effect of water on the flavor. The water must be perfectly clean so that cold extraction brings out the sweetness and fullness of the coffee.
Summary: Water is the soul of coffee
Water quality has a decisive impact on the taste of your coffee, whether it's espresso, filter coffee or cold brew. By paying attention to the purity, mineral balance and pH of your water, you can ensure that your coffee tastes exactly as it should.
As a professional, optimizing water quality is a step that can separate good coffee from excellent.
