Many espresso machines and fully automatic coffee makers have slots for water filter cartridges. But are the pluggable filter cartridges actually any good? We tested 5 models and summarized the results in a video about plug-in water filters from BWT, Brita, Jura, Lelit, and Sage.
Importance of Water for Coffee Preparation
Water plays a central role in coffee preparation. This is no surprise, as every coffee beverage consists of well over 90% water. Nevertheless, for a long time the focus was mainly on protecting the machine and less on the effects of water on taste. Conveniently, water that tastes good in coffee is also water that protects machines. We recommend the following water hardness levels.
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
In our detailed water article we have covered the reasons and basics of water chemistry in detail. We also provide tips on which methods can be used to test water at home and what the limitations of filtration are. Another article focuses on filter water pods. We are currently working on a test of filter water jugs.
Water Filter Cartridge Test Results
The following summary of test results shows how each water filter cartridge performs. For the test, the filter cartridges were first prepared as recommended by the manufacturer. Then, one liter of water was pumped through the filter and measured. This was followed by five more liters and another measurement, then five more liters and another measurement. Finally, 10 liters were pumped through the filter and measured again.
Measurements were made using a drop test kit for hardness measurement and a conductivity meter.
Results in German hardness = dH.
Special Pump for Measuring Filter Cartridges
Normally, the filter cartridges are inserted into the water tanks of coffee machines. The water is pumped through the filter cartridge by the coffee machine and then heated. Measuring already heated water would not have given us usable results, since the water changes through heating.
That is why we used an external pump, which allowed us to regulate the flow rate to match the flow speed of espresso machines.
Does the Input Water Matter?
The tests were conducted with water with an input hardness of 13° total hardness German hardness and 11° dH alkalinity. Filter performance was adequate even with water hardness up to 25° German hardness. In principle, the filters achieve their target filter performance up to approximately the target value. However, the durability of the filters is significantly reduced when harder water is used.
Are Water Filter Cartridges Recommended?
3 out of 5 filters delivered good results throughout the entire test period. Filter performance is also better than, for example, with countertop water filters. That's just a small preview of the results of our countertop water filter test.
The Jura Claris Filter shows its strength once a few liters have run through the canister. Overall, it does a good job and enables good coffee while protecting the coffee machine at the same time.
The Brita Intenza also achieves good target values, especially from a flow-through of 5 liters onward. Conclusion: good for coffee and machine, also quite strong for filter coffee because it leans toward the softer range.
The BWT Best Cup Water Filter remains somewhat too hard. Initially it doesn't get going, and even after some flow-through the values only scratch the target range. Although after 6 liters of flow-through a good hardness window is briefly achieved.
The Lelit MC747 is not a decarbonizer but a desalter. It removes magnesium and calcium from the water but leaves the alkalinity. This protects the espresso machine but doesn't prepare the water well for brewing delicious coffee. The Lelit filter is not well suited for the preparation of sensorily high-quality coffee.
The Sage Filter gets going after about 11 liters flushed through and then brews water on the softer side. This filter can be installed in espresso machines like the Sage Barista Pro or Sage Barista Touch. The water values are also very well suited for brewing filter coffee.
If you want to learn more about the perfect water for coffee, you can find all our articles on the subject here.
