Excellent information! Being a coffee nerd, I got into water. I went to AI and asked it the following: Give me the top 5 brands of bottled water that meet these criteria for brewing coffee that typically meet these parameters: Chlorine-free Around 150 ppm TDS Around 40 ppm alkalinity Free of scale-forming minerals It asked many questions, then honed what it was telling me to the water I use, which is Crystal Geyser, and always in a Chemex. AI asked me which plant and gave me the following results: Option A — Ultra-clear, bright For 500 g brew water - 125 g Crystal Geyser (Johnstown, NY) - 375 g distilled Option B — “Target spec” bright-but-balanced For 500 g brew water - 125 g Crystal Geyser (Johnstown, NY) - 375 g distilled - 0.045 g Epsom salt (MgSO₄·7H₂O), food-grade My coffee has never tasted better!!

If you want to know the 5 brands it first came up with here are the results:Here are five bottled waters that coffee folks use because they’re close to your target profile. I’ve listed the typical numbers (approx.) and any caveats. 1. Volvic (France) — often closest overall 2. Arrowhead Mountain Spring (US West) 3. Acqua Panna (Italy) 4. “Alive Waters” / Opal Springs (Pacific NW, various labels like Gelson’s, Earth2O) 5. Icelandic Glacial (Iceland) Why these: the general coffee-water guidance is chlorine-free, around 150 ppm TDS, ~40 ppm alkalinity, and low scale-forming minerals. None of the widely available bottled waters hit those numbers perfectly everywhere, but the five above are the nearest common options, with Volvic and Opal/Alive usually tasting most balanced without scaling gear.