Optimal espresso requires water with specific qualities. Filtering impurities like chlorine, sediment, and excess minerals enhances the flavor profile, preventing bitterness and off-notes. Proper filtration also protects delicate espresso machine components from scale buildup, prolonging their lifespan and ensuring consistent performance. For example, a filter might remove calcium and magnesium ions which contribute to hardness, preventing blockages in the machines internal pathways.
Maintaining water purity is crucial for achieving a quality espresso. Untreated water can negatively impact the taste, aroma, and crema. Moreover, scale accumulation due to hard water can lead to costly repairs or premature machine failure. Historically, espresso preparation has always emphasized water quality, with early practitioners recognizing the impact of source water on the final brew. The advent of specialized filtration systems represents a significant advancement in consistently achieving optimal espresso in various environments.