EMPIRICAL WATER is devoted to one cause:

Producing excellent brewing water for specialty coffee & tea.
Why? Because the unavailability of excellent brewing water is the greatest impediment to quality in specialty brewing today. And yet, brewing water also has the most potential of any variable to improve the sensory attributes of coffee & tea.
How? Through relentless research & development, time & labor-intensive methods, and the use of calcium carbonate - The #1 most important mineral in a brewing context. This entails a large form factor and high shipping costs, but quality comes first.
Empirical Water marks the next generation of specialty brewing water.
Spread the word.

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Hardness and Buffer is included in your order.


To prepare the default 1x brew water,

  1. Mix 50 grams Hardness with 950 grams zero TDS water.
  2. Add 0.50 mL Buffer (B).


To prepare the default 1x brew water,

  1. Mix 100 grams Hardness (H) with 900 grams zero TDS water.
  2. Add 0.50 mL Buffer (B).

Buffer Guide

As a starting point, use:

  • 0.50 mL Buffer for light roast coffee and any tea
  • 0.50 mL x2 Buffer for medium roast coffee
  • 0.50 mL x3 Buffer for dark roast coffee

For higher intensity, use less buffer. For lower intensity, use more buffer. It's recommended to adjust buffer amount in increments of 1 drop.

Extraction Booster

The Extraction Booster (EB) is a dropper bottle of mineral concentrate, designed to help extract ultra light coffee roasts.

The effect is increased flavor intensity and definition.

As a starting point, add 0.25 mL Extraction Booster per liter of 1x brew water. Add up to 0.50 mL for the maximum effect.

Not recommended for brewing tea or darker coffee roasts.

Mineral Composition

All minerals in Empirical Water can be found in natural mineral waters at comparable concentrations.

Ion Amount Present in 1x Empirical Water (mg/L) 
Calcium 9.3
Magnesium 2.8
Chloride 6.9
Sulfate 8.8
Sodium 7.4
Bicarbonate 38.8
TDS 74.0



Hardness: Calcium carbonate, magnesium sulfate, calcium chloride, magnesium chloride.

Buffer: Deionized water, sodium bicarbonate.

Extraction Booster: Deionized water, magnesium sulfate.


Can I mix Empirical Water with tap water, spring water, reverse osmosis or other drinking water?

Empirical Water is an ultra fine-tuned mineral profile. As a result, it's crucial to select a dilution water that contains absolutely zero TDS. Tap water, spring water, and even reverse osmosis water have too much mineral content to be used as dilution water.

What is zero TDS water, and where can I find it?

TDS = Total Dissolved Solids, which are usually minerals. Zero TDS water is water that contains no minerals.

Deionized - Best option. Pick up a Zero Water pitcher and enjoy Empirical Water the way it was meant to be. Zero Water pitchers save money over time compared to buying distilled water. Ideally, feed your Zero Water pitcher or other deionization system with the lowest TDS water you can find, typically reverse osmosis, to conserve the life of your deionization filter/resin.

The recommended long-term solution is an under-sink reverse osmosis unit with a deionization stage.

Distilled - Most grocery stores carry distilled water. Recommended brands: Arrowhead Distilled, Good & Gather Distilled (find at Target), Ice Mountain Distilled

There is quite some variance in distilled water quality, so please try a few different brands to find the one that tastes best.

Reverse osmosis - Low TDS, not zero. Do not mix Empirical Water with reverse osmosis water unless it has been fully deionized.

What is the shelf life of Empirical Water?

An unopened bottle of Hardness concentrate will stay fresh for 1 year. Once opened, it's recommended to use it within a month. The dropper bottle concentrates will stay fresh for 2 months (at minimum), which is the lowest order frequency on offer.

How should I store the provided concentrates?

The concentrates can be stored at room temperature or in the fridge.

What makes Empirical Water different from other brewing waters on the market?

What's the difference between the Coffee and Tea Editions?

Differentiating these Editions is a project that's currently in the works. For now, they are the same water, and can brew tea and coffee equally well.

Can I use Empirical Water in my espresso machine?

Empirical Water produces a non-zero but still minimal amount of scale when boiled. If you use your espresso machine every day, the overcautious recommendation is to check your espresso boiler for descaling needs once a year.

In practice, we've never observed scale build-up or corrosion in our machines, probably because the boiler water re-absorbs most of the calcium carbonate when cool. As a result, we've never actually needed to descale one of our machines before.

Can I drink the concentrates?

Do not drink the concentrates before diluting them into brew water according to the instructions higher up on this page.

How do I manage my subscription(s)?

Log into your account (top right corner), then click "Manage Subscriptions" under Account Details.