Why is the right water so important for coffee?

Bruno Martins
2021-05-12T14:00:00+02:00

Disturbing substances in the water can affect the taste, consistency and appearance of your coffee or tea.
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Water filters - How to optimize your drinking water and protect your household appliances

In Germany we have very good drinking water, but in most regions it is far too hard. Coffee made with water that is too hard does not develop its full aroma, tastes rather bland and sometimes even slightly mineral. A water filter can significantly improve the quality of the water. Water filters are available in different types and price ranges. The different water filter systems can soften the tap water and thus ensure better taste, but there are also systems that also filter out other undesirable substances. This reduces limescale, chlorine and heavy metals such as lead or copper in tap water. We have put together a list of what each filter system can do for you here.

water filter with carbon & ion exchanger

Water filters with carbon cartridges have been around for a long time in the form of practical table jugs with an inserted filter cartridge filled with loose carbon granules. The water poured in runs slowly through the filter, which filters out most of the temporary water hardness. If these simple filter cartridges have an integrated ion exchanger, parts of the permanent water hardness such as magnesium and calcium ions are also removed and replaced with sodium ions. This makes the water significantly softer and can be used for enjoying coffee or tea.

This classic water filter technology with carbon cartridges and ion exchangers is very easy to use, can be used anywhere and scores points per liter of treated water due to the low purchase price and inexpensive filter cartridges for refilling.

Another advantage of these systems is that not all minerals are completely filtered out. As recommended in our article on the perfect water for portafilter machines, medium-hard to almost soft water is best for the coffee aroma. The drinking water can therefore still retain a "good" mineral content for the taste.

Water for the coffee machine or for making tea can be produced easily with these simple filter systems, but the quantitative filter performance is relatively low and the systems tend to become contaminated, particularly when the treated water is left standing for a long time and especially when it is used infrequently or when it runs dry. Correct handling and hygiene are very important here. Cleaning the jug frequently, e.g. in the dishwasher, and regularly changing the filter cartridges is very important. High-quality systems have a change indicator - but with simple systems a small sticker on the table jug also helps to indicate the next change date. This should definitely be adhered to, because these systems release the filtered substances back into the drinking water when the filter performance is reached, in addition to the substances that we want to filter out of the drinking water...

activated carbon water filter

Here, it is not loose carbon granules that work in a filter, but rather a block of finely ground carbon pressed under high pressure - often in several layers. The activated carbon filter works very reliably against pollutants and limescale.

The pressed carbon block has very fine pores in the micrometer range and therefore an extremely large surface area and a very high filtering effect. The activated carbon block even removes pollutants from the tap water, such as heavy metals, pesticides, germs, bacteria, fungi, hormones and even undesirable substances such as chlorine.

The performance of activated carbon filters is so good that they can also be used to filter water from natural bodies of water ready for drinking. Adventurers and world travelers even find small systems with activated carbon filters for the treatment of drinking water in special bottles.

Activated carbon filter systems are available in different sizes, such as a table jug or a built-in system with an under-sink connection. The working principle is extremely simple: as many minerals and pollutants as possible are filtered out of the water and held on the huge surface structure of the pressed carbon. The result is almost pure and uncontaminated water that only cannot bind the magnesium and calcium ions dissolved in the water, i.e. the components of the permanent water hardness. If you combine an activated carbon filter with an ion exchanger, you get wonderfully pure and softer water.

But activated carbon cartridges also need to be replaced regularly. The advantage, however, is that the extremely large surface area of ​​the filter binds the pollutants very firmly and thus clogs the pores. However, the filtered-out substances are not returned when the filter is "full" as is the case with cheaper filters made of simple carbon granules. However, the flow rate drops rapidly and is a sure sign that it is time to replace the filter.

Reverse Osmosis – The Filter Technology of the Professionals

Reverse osmosis uses the principle of osmosis, in which two different concentrated liquids are separated only by a semi-permeable membrane and strive to establish a balance of concentration.

When treating water using reverse osmosis, this process is applied using pressure and the direction of the water flow is reversed. The water is forced under pressure into the filter cartridge containing a solution that contains a high salt content and is pressed through a membrane made of a polymer material that is only permeable to small water molecules. This means that almost pure water collects behind the membrane. All undesirable components are flushed out of the drain via the filter.

Reverse osmosis systems filter out everything from the drinking water that could interfere: heavy metals, viruses, bacteria, nitrates, limescale, but also dissolved magnesium and calcium ions. The efficient filter technology comes at a price and requires a corresponding amount of space. They are very suitable for under-sink installation for the permanent water connection to a coffee machine or directly to the tap for permanently soft water. Such soft water is less suitable for coffee or tea because it is too acidic and can interfere with the fine coffee aromas. High-quality treatment systems therefore re-mineralize the water until it is neutral and is ideal for making coffee or tea.

Optimal water quality through pre-filtration, carbonate hardness reduction, activated carbon filtration

Limescale deposits and associated machine failures are specifically reduced, service and repair costs are reduced

Removal of undesirable taste and odor substances in the filtrate (also in the blend water) for optimal quality of the final product

A filter head concept for all sizes in different designs for individual requirements

quick-change system with secure locking

Integrated flushing and venting valve

Conclusion

The water hardness and the pH value affect the taste of the coffee. Our predominantly hard water in Germany has a basic pH value and neutralizes the fine acids and desired flavors of the coffee. Even simple water filters help with water that is too hard. Simple carbon granulate and activated carbon filters can be bought in stores for little money. However, the carbon filters should always be combined with an ion exchanger for optimal effect. However, filter systems with carbon granulate require a lot of maintenance. If they are used little or not cleaned properly, they tend to become contaminated. Activated carbon filters are insensitive here, but also a little more expensive. Reverse osmosis systems clean and filter the water very intensively, but can only be used to prepare coffee or tea with subsequent mineralization.

A good carbon water filter with ion exchanger compensates for deficiencies such as hard water and is available for little money. A sensible investment to extend the life of your coffee machine and improve the good taste of the coffee.