Coffee water filter selection, what you need to know?

In a world of new specialty coffees and advanced coffee equipment, people are suddenly interested to know, “how does water really affect my coffee brewing?” And “why doesn’t it taste the same when I make it somewhere else?” People are eager to learn how to select the right coffee water filter for this cafe.

Coffee water filter retailers have been chanting “espresso is 90-ish% water” for years

Many years ago, Everpure discovered that certain water contaminants have an adverse effect on coffee machines and coffee brewing. This led to collaboration with machine manufacturers, coffee producers and cafe operators to solve these issues around the world. Over the years, Everpure built a vast bank of knowledge which has allowed them to develop a water standard for coffee. Out of this water, the standard has come innovation to address these issues no matter where you serve coffee.

Through carefully selected filtration, multi-store operators can achieve a consistent coffee taste from Sydney to Perth to ensure customer satisfaction and trust in your product. Australia’s water conditions vary state by state, even suburb by suburb in some places, therefore it’s important to recognise that no single coffee water filter solution will fit all locations. So don’t be fooled by one filter type that fits all companies.

The following points should get you asking the right questions.


These are the particles in the water such as dirt, silt and sand. High levels of turbidity can cause abrasion damage and clogging of the machine’s values therefore it’s recommended that water for coffee not exceed 0.5 NTU. To achieve this we recommend a coffee water filter rated at or below 5 microns.

Chlorine and Chloramine

The only aroma coming from the cup should be the smell of coffee. Excess levels of Chlorine or Chloramine can oxidise the coffee aromatics, oils and flavours, negatively impacting the coffee. Good quality carbon filtration will usually be enough to remove these. If you have Chloramine in your local water, seek a specific Chloramine rated coffee water filter.


Alkalinity or Carbonate hardness levels should be below 100ppm. Above this level, water flow through the coffee grounds can slow and bitterness may be noticed. Machine scaling is also more likely. Alkalinity lower than 100ppm however doesn’t assure you of a scale-free machine. There are many more factors to consider in preventing scale formation. Treatment of Alkalinity with a blendable softener like Everpure’s Claris Ultra Series is recommended.


Ideally, the total hardness should be 17 – 85ppm even though what is an acceptable limit is open to debate. Water at the lower end will cause over-extraction of the aromatic oils, whilst water that is too hard will under-extract, this then leads to a bitter or sour taste in the coffee.

It’s the hardness reacting with the carbonates (alkalinity) that creates scale in coffee machines. The scale will build up on heating elements, acting as an insulator, preventing efficient heating of the water and ultimately leading to a failure of the element, blocking small valves and reducing water flow and energy efficiency.

In hard water areas, Total Hardness can be reduced by softening or Reverse Osmosis (RO). In areas of relatively soft water like Melbourne, over-engineering with softeners or RO will impair the coffee flavour because all the good mineral has been removed. The use of scale inhibiting filters containing Phosphate (such as Everpure 2CB-GW, 2CB5-S, 4CB5-S) is a better solution because it will leave the mineral profile where is should be.

Total Dissolved Solids (TDS)

This is basically everything dissolved in the water (Hardness, Chloride etc.) and is the water’s “aromatic oils”. Suggested levels for coffee brewing are between 70 – 200ppm. High levels of dissolved solids can increase acidity, give “heavy” extraction and impart off-tastes and odours. Low levels can give a sour taste and a lightness to the extraction as the water itself has no real body. The most effective way to reduce TDS above 200ppm is through blendable Reverse Osmosis technology like Everpure’s MRS Series.


Water with a pH lower than 7 is considered acid and could, under extreme conditions, lead to corrosion of the equipment. It will also impart sourness to the extracted coffee. Water with a pH greater than 7 is considered alkaline and can cause bitterness in the coffee. In reality, a pH of 7 is difficult to achieve, therefore an ideal range would be between 6.8 and 7.4.


Chlorides are common around Australia, predominantly in Perth, up and down the WA coast, Adelaide, regional South Australia and regional Queensland. With a myriad of metals used in modern coffee machines, it’s difficult to nominate an exact limit. We recommend action is taken if levels exceed 50ppm.

Reverse Osmosis is the only effective method of reducing Chlorides. Softening filters will have no effect and often make the situation worse because they remove the hardness which was partially balancing out the Chloride.

We hope this article was helpful in your quest for consistent quality coffee. For more information, please review coffee filtration here.

Water Testing

Maybe you have no idea what’s in your water? Why not order a 5 parameter water test from our lab to get you started with selection.