Countertop water filters are a practical and easy way to filter water for good coffee. In almost all areas, tap water is generally too hard to make good coffee. At the same time, hard water also poses a risk to your coffee machine, as it encourages limescale buildup.
With table water filters or other filtering methods, water can be filtered so that it tastes delicious and is also suitable for coffee machines and espresso machines.
In this test, table water filters from BWT , Brita , Lotus Vita , LARQ , Aarke , Yucona and Peak were tested.
Good water values for making coffee
Perfect water for filter coffee:
Total hardness: 2 – 3 °dH
Alkalinity: 1 – 2 °dH
Perfect water for espresso:
Total hardness: 3 – 6 °dH
Alkalinity: 2 – 4 °dH
We've written more about the perfect water for coffee in our detailed blog post about " Coffee Water ." Another test summarizes the results of the most commonly used plug-in filter cartridges for espresso machines and fully automatic coffee machines. So-called water filter pads can also soften water, but they take time.
To analyze your own water, we recommend conducting a test using titration drops. In Switzerland, you can purchase the test kit from bwt , and in Germany, the test kit from Brita .
Table water filters compared with water pads and plug-in filters
Plug-in water filters generally provide the best water filtration. They are inserted into the water tank. The suction from the machine's pump draws the water through the filter with pressure or force. This achieves good filtration performance.
Water filter pads are placed in a water tank, and the water isn't moving. Therefore, the filter's performance only develops over many hours. In our test, we tested the filter performance over many hours. Only after well over 20 hours did the water values reach the target range.
Countertop water filters are positioned between plug-in filters and filter pads. The water flows through the filter cartridges by gravity and is filtered in a few minutes. Some of the tested filters achieved good target values because they were designed for decarbonization. Other filters missed the target values, as the test shows.
We've created two videos about countertop water filters. First, there's our main video with all the details and additional explanations.
On the other hand, we have recorded a second version that summarizes the results briefly and concisely in just a few minutes.
How was the test carried out?
The benchtop filters were first prepared according to the manufacturer's instructions. Then, 1 liter, 5 liters, another 5 liters, and then 10 liters of water were filtered. After each filtering, samples were taken and measured using test drops to determine water hardness and a conductivity meter.
LARQ Filter and Lotus Vita Filter
The Lotus Vita and the LARQ filters were both recommended to us for testing by the coffee community. Both filters are presented as a general water quality improvement, not specifically as filters for preparing water for coffee. Nevertheless, such a test is fascinating and reveals the characteristics of different water filters. Both filters effectively filter the total hardness, i.e., calcium and magnesium, from the water. However, they barely reduce, or do not reduce, the alkalinity. The hardness of our incoming water is 13 German hardness (total hardness) and 10 German hardness (alkali hardness). While the total hardness is reduced, the alkalinity is too low to effectively filter water for coffee.
We recommend both filters to effectively remove contaminants. Reducing the overall hardness is sufficient to protect the coffee machine. The alkalinity is too high to brew delicious coffee.
Brita and BWT table water filters, Peak and Aarke
The four table water filters from Brita , BWT , Peak , and Aarke are all capable of filtering good coffee water. The filter performance of the Brita filter and the Aarke filter was good, while the BWT filter was not as effective. To achieve the exact target values, the BWT filter would need a second filtering cycle with our raw water. The yucona filter also does not achieve the target with a single filtering cycle and must be used a second or third time depending on the water hardness.
The Peak Filter is the most versatile filter, as a flow reduction allows for more or less filtering. This is particularly useful for raw water inlets with a total hardness of 10 to 15 dH. For water like ours with a total hardness of around 13 dH, a filter setting of 4.5 is certainly perfect. Anyone who only has to deal with a total hardness of 12 dH will certainly be able to cope with a lower filter capacity. This flexibility allows for individual adaptation to local conditions – great!
Unfortunately, the build quality of the Peak filter isn't great. The pot feels cheap and unstable. The Aarke filter clearly scores points here. The filter is made of glass, and the filter insert is made of stainless steel. The filter is self-refillable and works best alongside a high-quality espresso machine.
Summary of results
Water filters from Peak , Aarke , Brita , and, to a lesser extent, BWT performed well in the test. The Lotus Vita filter and the LARQ filter are primarily designed to filter out foreign particles and desalinate the water. However, they do not sufficiently reduce alkalinity. The high alkalinity retained buffers the coffee's acidity, which is important for the balance of a complex and delicious coffee.
Although the Yucona filter is a decarbonizer, it is only of limited effectiveness. Of all the filters suitable for coffee, it has the lowest filtration efficiency in reducing alkalinity. Multiple filtering of the water is necessary to achieve the target values.
