Should I use distilled water for coffee?

The common misconception that 'pure' water makes the best coffee ignores the fundamental chemistry of extraction. Water is not merely a carrier for coffee; it is an active participant. When you brew, water acts as a solvent, and its ability to pull flavor compounds—such as acids, sugars, and oils—from the cellular structure of the coffee bean depends entirely on its mineral content. Distilled water, having been stripped of all ions, lacks the 'buffering capacity' provided by bicarbonates. Without this buffer, the water cannot neutralize the organic acids extracted from the coffee, leading to an unbalanced, aggressively sour, and hollow-tasting brew. From a producer’s perspective, this is a tragedy: months of meticulous cultivation, selective harvesting, and precise processing are effectively erased when the final extraction is performed with water that cannot articulate the coffee's inherent sweetness or body. While some enthusiasts experiment with 'custom' water profiles to highlight specific notes, they are adding minerals back into distilled water, not using it in its raw state. The goal is not purity, but a balanced mineral composition that acts like salt in cooking—amplifying the coffee's natural characteristics rather than stripping them away. Relying on distilled water is a technical error that prevents the coffee from reaching its potential, regardless of how high the quality of the green bean may be.