Coffee is approximately 98% water. That statistic is easy to gloss over, but it has a real impact on what ends up in your cup. The mineral content of your water — specifically magnesium, calcium, and bicarbonate levels — directly affects how well it extracts flavor compounds from coffee grounds. Too few minerals and the water is "soft" and under-extracts; too many and it can over-extract or produce a chalky, flat cup.
Tap water varies enormously by region, and even filtered water often has an unpredictable mineral profile. At Deep Space Coffee, we don’t leave that variable to chance. Here’s what we use.
Third Wave Water — For Espresso
For espresso, we use Third Wave Water mixed with distilled water. Third Wave Water packets are formulated to hit the Specialty Coffee Association’s ideal mineral targets for espresso: a specific balance of magnesium and calcium that maximizes sweetness and body while keeping bitterness in check.
Espresso is an unforgiving brew method — high pressure, short contact time, concentrated extraction. The water profile has an outsized effect on the final shot. Third Wave Water’s espresso formula is designed to bring out caramel and chocolate notes while softening harsh edges, which aligns perfectly with the kind of coffees we roast.
Using distilled water as the base also means zero variables from local tap chemistry. You get the same cup every time, regardless of where you are.
Empirical Water — For Drip & Pour Over
For drip and pour over brewing, we use Empirical Water drops with a ZeroWater pitcher. Empirical takes a more nuanced approach to water formulation — their profiles are designed for filter coffee specifically, with mineral ratios tuned to highlight clarity, acidity, and the delicate aromatic compounds that make single origin coffee worth drinking.
Where Third Wave Water leans toward body and sweetness (ideal for espresso), Empirical Water profiles tend to emphasize brightness and definition — exactly what you want when you’re trying to taste the difference between a Kercha Haruse from Ethiopia and a natural process from Bolivia.
For light roasts especially, water with the right magnesium-to-calcium ratio can make floral and fruit notes dramatically more expressive. Empirical Water helps us get the most out of every origin we carry.
Why This Matters for You at Home
You don’t need to go this deep to brew great coffee — but if you’ve dialed in your grinder, your technique, and your recipe and the cup still isn’t singing, water is often the missing variable.
A few practical options:
- Third Wave Water or Empirical Water — the easiest way to control your water profile without a chemistry degree. Mix with distilled water or use a Culligan ZeroWater pitcher per the instructions.
- Filtered water (Brita, etc.) — better than tap in most cases, but mineral content will vary. A reasonable middle ground.
- Bottled spring water — check the label for TDS (total dissolved solids). Aim for 75–150 ppm for most brew methods.
- Avoid distilled water alone — zero minerals means poor extraction and a flat, hollow cup.
The Takeaway
We roast to order and ship within 48 hours because freshness matters. We use Third Wave Water for espresso and Empirical Water for drip because water matters too. Every variable in the cup is worth paying attention to — and water is one of the easiest to control once you know it’s a variable at all.
Want to go deeper on brew technique? Check out our Brew Guides or read about how to dial in your grind for pour over.