Machines connected to the water main must have a water softener. The appropriate degree of water hardness for an espresso is 9 °dH.
- The ion exchange resin water softeners are used in accordance with the volume of water and not in accordance with the amount of time elapsed.
- In theory, 30 to 40 g of salt should be used per cubic meter of water, and according to the German degree of hardness and type of ion exchange resin.
- With the water softener which regenerates with large sea salt, repeat the regeneration after every 1500 to 2000 beverages are prepared.
- In the automatic softener, the program must be reset in each cycle. If the water stays in the softener for too long, it becomes ‘over-regenerated’ and begins to affect the quality of the coffee. In that case, it is necessary to let out a certain quantity of water in all exhausts in order to let the hard water from the water main come into the purifier and establish the minimal hardness.
- If during the regeneration of the softener, the ion exchange resin changes color (due to the sedimentation of organic matter, treatment with chlorine, etc.) or contains other sediments, it must be changed.
Irregularities in the passage of water from the pipes to the softener
- Is the softener regularly treated with salt (purified)? Because if it is not, limescale is created and it significantly affects the passage of water through the pipes.
- Is the water tap from the water main regularly used?
- Is the pressure of the water main constant, but not higher than 4 to 5 bars (because if it is higher, a relief valve should be used to reduce pressure before it reaches the softener)?
- Does the machine have a standard balancing pump?
Water with a low percentage of calcium
- If water hardness is less than 9 °dH, a water softener is not necessary. This, however, is not the case in the region.