Water, comprising over 98% of filter coffee, influences extraction and taste through its mineral content. Baristas are increasingly using custom water profiles and pre-made concentrates to fine-tune flavors like acidity and sweetness. Experts note that precise mineral adjustments can elevate coffee's nuance and complexity.
Water forms the foundation of pour-over coffee, making up more than 98% of a filter brew. Its mineral composition actively shapes flavor perception, much like salt enhances dishes by amplifying depth and balance. Baristas now treat water as a key brewing variable, adjusting minerals to control aspects such as silkiness, crispness, and aftertaste length.
Jordan Tachnakian, the 2024 World Cezve/Ibrik Champion and head of quality at Terres de Café, explains: “It awakens, carries, and elevates every nuance in coffee.” He adds that even minor changes in minerals can alter the coffee's weight on the palate and finish. Industry figures like Maxwell Colonna Dashwood and Christopher Hendon have spotlighted water chemistry in specialty coffee.
Essential minerals include calcium and magnesium for extraction balance, with ideal pH levels between 6 and 8 maintained by bicarbonates. Potassium extends sweetness, chloride adds roundness, sodium boosts flavors while curbing bitterness, and sulphate highlights floral and citrus notes.
This focus has spurred innovations in water products. At the 2024 World Brewers Cup, over 70% of competitors used Apax Lab concentrates; winner Martin Wölfl combined Tonik, Jamm, and Lylac for a balanced profile with his anaerobic natural coffee. Terres de Café collaborated with Apax Lab's Simon on a custom mineral kit tailored to their roasting and local water.
High-end cafés offer customer tastings, splitting brews to demonstrate mineral impacts. Tachnakian notes: “If you split your brewed coffee into two cups, add a single drop of minerals to one and leave the other untouched, you will taste the difference – in flavour, texture, and overall expression.”
Third Wave Water, featured on Shark Tank in 2017 and acquiring Perfect Coffee Water in 2025, provides sachets for various roasts. Founder Charles Nick states: “One of the most important differences in mineral content between light and dark roasts is alkalinity... you want more alkaline water for dark roasted coffee to smooth out flavours and enhance the nutty, chocolate notes.” Many cafés now use remineralized reverse osmosis systems as a blank canvas for custom profiles.
While DIY recipes demand expertise to avoid flavor distortion, pre-made options simplify access. Nick describes them as “a gateway into specialty water for coffee,” requiring no scientific background. Tachnakian concludes: “Water is fundamental to truly enjoying a great cup of coffee... A well-designed filtration system, combined with thoughtful mineral adjustment tailored to the coffee, already makes a significant difference.”