The Science of Coffee The two ingredients in water that ruin your coffee, and the ancient story behind them
Jul 28, 2025
Explore the surprising impact of water quality on your coffee's flavor. Discover how two key ingredients—calcium and hydrogen carbonate—can make or break your brew. Journey back 550 million years to a time when Earth was a lush paradise, and learn about the cosmic origins of today’s water. Uncover the challenges posed by modern tap water and how ancient life forms shape our current water sources. This episode reveals the intricate connection between water chemistry and the coffee experience, making each cup a tale of evolution.
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Water Tasting Experience
- James Harper tasted tap water and filtered water in Wiesbaden both alone and with coffee.
- He found filtered water makes coffee taste more vibrant, despite tap water tasting better alone.
Key Water Ingredients for Coffee
- The two invisible ingredients in water crucial for coffee are calcium and hydrogen carbonate.
- Having some but not too much of these makes water good for brewing specialty coffee.
Cyanobacteria's Earth Transformation
- Cyanobacteria created the Great Oxidation Event, producing oxygen and removing toxic iron from oceans.
- This transformation made water less toxic and air breathable, crucial for life and coffee quality.
