Water Quality and Espresso: Why It Matters More Than You Think

Water Quality and Espresso: Why It Matters More Than You Think


When it comes to crafting the perfect espresso, enthusiasts often focus on the coffee beans, the grind size, or the espresso machine itself. However, there's a critical, often overlooked component that can significantly impact the quality of your espresso - water. In this blog post, we'll dive into why water quality is not just a minor detail, but a key ingredient in your pursuit of the perfect espresso shot.

The Role of Water in Espresso Making

Espresso, at its core, is a simple beverage made from just two ingredients: coffee and water. While the coffee beans are the star, water is the unsung hero, making up about 90% of your espresso shot. The quality of water can affect everything from the extraction of flavors to the overall taste and aroma of your espresso.

Understanding Water Composition

Water isn't just H2O. It contains various dissolved minerals like calcium, magnesium, and bicarbonates, which play a significant role in the brewing process. The concentration and balance of these minerals determine the 'hardness' or 'softness' of your water.

  • Hard Water: High in minerals, especially calcium and magnesium. It can enhance certain flavors in coffee but may lead to limescale buildup in your machine.
  • Soft Water: Low mineral content. While it's gentler on your espresso machine, it might not extract the coffee flavors effectively.

The Perfect Balance

The goal is to find a balance in water hardness. Water that's too hard can over-extract coffee, leading to a bitter taste, while excessively soft water can lead to under-extraction, resulting in a flat, uninspiring espresso. The Specialty Coffee Association (SCA) offers guidelines for the ideal water composition for brewing coffee, which can be a great reference point.

Filtering Your Water

Using filtered water can dramatically improve your espresso. Filtration systems can remove unwanted tastes and odors, ensuring the water doesn't impart any off-flavors to your espresso. Moreover, it can help in maintaining the right mineral balance and protect your espresso machine from scale buildup.

Testing and Adjusting Your Water

To truly optimize your espresso, consider testing your water with a home testing kit. This can provide insights into its hardness and overall composition. Based on these results, you can adjust your water, either by using a water softener for very hard water or adding minerals to overly soft water.


The quest for the perfect espresso is a journey of details and precision. Water quality, often underestimated, is one of these crucial details. By understanding and controlling the water you use in your espresso brewing process, you can elevate your coffee experience to new heights. Remember, great espresso is not just about the beans or the machine; it's also about the water that flows through them. 

Back to blog