What is TDS and why does it matter?Updated a month ago
TDS stands for "Total Dissolved Solids," and represents the amount of "stuff" that is dissolved in a liquid. This stuff can be organic matter, minerals, and even some chemicals (depending on where your water is coming from).
Why does TDS matter?
TDS matters because it effects the level of extraction you can get out of your coffee. Your coffee needs minerals in the water you brew with so you can pull the desired flavor out of the grounds. Empty water (water with 0TDS) will leave your coffee tasting dull and flat.
The SCA (Specialty Coffee Association) created a water standard that acts as a guide for your coffee brewing water. The recommended TDS is a target of 150 TDS with an acceptable range of 75-250 TDS.
TDS will not tell you the exact amount of individual minerals are in your water, just the total amount. This helps provide a benchmark to help you dial in the right minerals. If you want to know which minerals are in your water and at what concentrations, you'll need specific tools like a photometer or titration kit to measure certain minerals.
Mineral Quantity and Quality:
The proper amount of minerals is not the only thing you want to be wary about, however. You also should look at the kind of minerals for your brewing water. Certain minerals can cause limescale to build up in your brewer or kettle, as well as corrode and damage the boiler in your espresso machine.
All of Third Wave Water's mineral profiles utilize permanent hardness to protect your equipment from limescale buildup. TWW Espresso Profile lacks chlorides, which are harmful for your espresso machine.
TDS and Water Hardness:
Water hardness is another term that refers to the amount of "stuff" in your water. Total hardness is measured as the sum of temporary hardness (measured in ppm) and permanent hardness (measured in ppm).
All Third Wave Water profiles contain only permanent hardness minerals. For our most popular profiles, Classic Light Roast Profile and Espresso Machine Profile, the total hardness is ≈150ppm; 0ppm temporary hardness + ≈150ppm permanent hardness.