Voda základní element kávy

Water - an essential element of coffee

Choosing the right water treatment is essential for a longer coffee machine life and for a perfect "shot" espresso. Unfortunately, in many cases, water treatment is insufficient or incorrectly designed. That is why coffee lovers and coffee makers La Marzocco, in conjunction with experts, have set quality water values that ensure perfect espresso, as well as increasing the life of coffee machines, and last but not least, protecting the health of customers.

To check the quality of your water, a quick and easy test has been created with which La Marzocco equips every coffee machine. For each device, you will find a water test kit containing 6 test strips with instructions.

Ideally, the water should be tested BEFORE treatment and again after filtration to ensure that your filtration is working to meet the recommended parameters.

After performing the test, you will find out which filtration system is recommended for your water by filling in the water calculator on the following pages:


The water analysis kit is only indicative and tests the presence of only the most essential substances that can be found in the water. For accurate data, contact a certified laboratory that has the equipment to perform a complete analysis. To refine the test, you should enter the TDS values that you will receive from the digital TDS meter measurement.

La Marzocco continues to emphasize the importance of using properly treated water to make the perfect espresso and to ensure the longevity of coffee machines. There are SCAA recommendations that prescribe values for perfect coffee extraction. However, from the point of view of the coffee machine manufacturer, they are somewhat different. Therefore, the values stated in the calculator are a compromise that will ensure an excellent drink and a long life of the coffee machine. We will be happy to explain to you - in an easy-to-understand form - what the individual values used in our "water calculator" mean

*** pH: The concentration of H + and OH- ions in the solution tells us how acidic or basic it is. The more acidic the solution, the lower the pH (higher concentration of H + ions). The more basic the solution, the higher the pH value (higher concentration of OH-ions). PH 7 is neutral, which is the ideal value for the water used to make an excellent espresso.

If the pH is higher than 8:

  • Espresso effect: overextracted, but pleasant espresso, weak aroma, very low pleasant acidity, but unpleasant bitter taste, low sweetness.
  • Effect on coffee machine: if the higher pH is caused by high salinity combined with low water hardness, corrosion of all metal materials will occur very quickly. If the high pH is caused by the high hardness of the water, the boiler will calcify very soon.

If the pH is lower than 6,5:

  • Espresso effect: unpleasant sour taste.
  • Effect on coffee machine: higher concentration of H + ions increases the corrosive effects of water on the pipes and the boiler of the coffee machine.

*** TDS: Total Dissolved Solids means the total content of organic and inorganic substances dissolved in the solution such as minerals, salts, metals in a given amount of water. The amount is given in ppm (parts per million) which is the same as mg / L.

TDS taller than 150ppm:

  • Espresso effect: unbalanced body and acidity, weak aroma, harsh taste.
  • Effect on coffee machine: mineral growth and slime in boilers.

TDS lower than 75ppm:

  • Espresso effect: weak body, bitter taste.
  • Effect on coffee machine: water becomes aggressive to the materials it comes in contact with, accelerating corrosion caused by other additional factors.

*** Total Hardness (total hardness)reflects the concentration of Ca2 + and Mg2 + ions and other minerals in the solution.Hardness measured by La Marzocco tesset is expressed in ppm (particulate matter)And per million)where one part per million is defined as one mg of calcium carbonate (CaCO3) in a liter of water. Calcium carbonate is the basic component responsible for limescale overgrowth.

Total Hardness taller than 150ppm:

  • Espresso effect: overextracted, harsh and bitter taste.
  • Effect on coffee machine: increased scale formation.

Total Hardness lower than 90ppm:

  • Espresso effect: flat body, low aroma, little or no crema, unpleasant acidity.
  • Effect on coffee machine: water becomes aggressive and can cause / accelerate corrosion in combination with other additional factors.

Total Iron: the high iron content gives the coffee (with added milk) a greenish tinge and a bitter iron flavor. The water flowing out of the boiler may be rusty in color.

*** Total Chloride (total chlorides)Chloride is a chlorine ion. It is formed by chlorine binding an electron to itself with appropriate Cl-. The best known chloride is sodium chloride (NaCl) or table salt, which dissolves very well in water.CHLORIDES ARE VERY COMMON IN COASTAL AREAS AND REGIONS SUPPLIED BY SURFACE WATER. CHLORIDES CAN ONLY BE REMOVED BY REVERSE OSMOSIS.

chlorideand taller than 30ppm:

  • Espresso effect: they increase the perception of acidity and emphasize phenolic compounds and astringency.
  • Effect on coffee machine: chlorides cause various terrifying manifestations of corrosion. Even rusting stainless steel.

*** Total Chlorine (total chlorine)Chlorine (Cl2) is a chemical element which is a very cheap, effective and affordable disinfectant used in water supply to kill bacteria in water, ie to prevent many diseases from water. ONLY ACTIVATED CARBON FILTERS CAN BE REMOVED.

  • Espresso effect: chlorine in combination with coffee phenolic ingredients causes a characteristic medical taste.
  • Effect on the coffee machine: chlorine increases the corrosive potential of water.

*** LSI index: Langelier saturation index taking into account pH, water hardness, alkalinity and water temperature, it determines the Langelier formula when water will tend to calcify or corrode.

  • LSI higher than 0.70: water will cause calcification.
  • LSI lower than 0.10: water will dissolve minerals and attack metals.

NOTE: test the water by taking a sample from the tap for COLD water that is NOT filtered. Use a fresh sample for each test. Always test the water in EVERY LOCATION (water quality may also be different in the sub block).