Best Water for Coffee: Does It Matter? Filtered vs RO vs Tap (Simple Science, Real Results)
Water is the most overlooked variable in coffee—and it can be the difference between a clean, sweet cup and coffee that tastes flat, sour, or “pool-ish.” In this Bilge Brew Show episode, Nate and a very knowledgeable (and very unserious) guest break down what actually matters: chlorine, mineral content (hardness), alkalinity, and why “pure” water like straight RO or distilled often brews worse unless it’s remineralized. You’ll get practical guidance for tap water, filtered water, bottled water, and RO systems—without turning your kitchen into a lab.
Show Notes: 00:00 — Why water can ruin great coffee (and why it’s not subtle) 02:10 — Chlorine: if you smell it, you’ll taste it in the cup 04:30 — The four water buckets: off-flavors, minerals, alkalinity, TDS 06:10 — SCA-style water targets (hardness, alkalinity, pH, “no chlorine”) 08:30 — Alkalinity explained: why too high = flat, too low = sharp 10:20 — TDS meters: useful, but they don’t tell the whole story 12:10 — Filter vs RO vs distilled: what each is good for (and where people mess up) 14:10 — Espresso machine owners: scale and corrosion risk basics 16:00 — Quick home test: brew the same coffee with two different waters 17:40 — Bilge Brew tie-in: bitterness variables and water consistency
Links for your show page:
SCA Home Coffee Brewers Standard 310-2021 (water ranges summary): https://coffeegeek.com/wp-content/uploads/2023/10/SCAGoldCupStandard.pdf
SCA Water Research Report (SCAE/SCAA water targets): https://sca.coffee/s/Water_Research_Report.pdf
SCAE Water Chart Report (alkalinity/hardness & corrosion notes): https://sca.coffee/s/SCAE-water-chart-report.pdf
SCA article on chlorine & aroma interactions: https://sca.coffee/sca-news/news-from-our-partners/water-and-the-taste-of-coffee
Bilge Brew blog (bitterness variables incl. water temp): https://bilgebrew.com/blogs/from-the-bilge-blog/what-makes-coffee-taste-bitter-and-how-to-avoid-it
EPISODE: Best Water for Coffee: Does It Matter? (Filtered vs RO vs Tap)
Episode page: https://bilgebrew.com/podcast/best-water-for-coffee
Ty the Bilge Brew Crew Sampler → https://bilgebrew.com/products/bilge-brew-crew-sampler?utm_source=podcast&utm_medium=shownotes&utm_campaign=best-water-for-coffee
What you’ll learn:
- Why “water quality” changes flavor more than most people think
- Filtered vs reverse osmosis vs tap (pros/cons + when each wins)
- Simple fixes that don’t require a lab setup
Resources mentioned:
- How to Brew Pour Over (without bitter/watery) → https://bilgebrew.com/blogs/from-the-bilge-blog/how-to-brew-pour-over-coffee-without-bitter-or-watery-results
- What Makes Coffee Taste Bitter (and how to avoid it) → https://bilgebrew.com/blogs/from-the-bilge-blog/what-makes-coffee-taste-bitter-and-how-to-avoid-it