When Eureka once again launches a "Mignon" espresso grinder, my reflexive response is, "Again?" Because by now, more than a dozen espresso grinders in the Mignon family are structurally very similar.
However, the Eureka Mignon Libra at least partially breaks new ground. It is the first Mignon with an integrated scale. The dispensed amount of ground coffee is no longer time-controlled but stopped when the target weight is reached in the weighed portafilter. This is brilliant if it works.
In this review, you will find out how well the Eureka Mignon Libra weighs, grinds, and integrates into the workflow alongside a home espresso machine. We also provide tips for a good workflow and categorize the strengths and weaknesses of the grinder.
There is now another version of the Eureka Libra, namely the Eureka Libra 65 All Purpose. We have also tested this grinder.
In a Nutshell - The Most Important Facts About the Eureka Mignon Libra in 2 Minutes
The Eureka Mignon Libra is a good espresso grinder. It builds on the strengths of the Eureka Mignon series, combines them, and is improved by the scale.
- The Libra's scale works well. It can be calibrated and precisely set.
- However, the ground coffee's ejection does not perfectly aim into the portafilter, causing coffee to scatter around the grinder during grinding.
- This is a typical problem with Eureka Mignon grinders, which is prevented in other models by tapping the portafilter during grinding.
- However, this procedure is not possible with the Libra because it cannot complete the weighing process.
- A dosing ring, which is not included, provides a remedy. With a dosing ring, the grinder is a good choice. Without it, it is a problem. Eureka now provides the ring in an additional box. See also Eureka's message to us at the very bottom of the page.
- Unfortunately, the dosing ring is not included. That is a weakness. However, it is available, for example, from Kai from Barista Legends*, also beautifully from Etsy made of wood* or from Wiedemann at Stoll*.
- To tare and thus to grind, our Eureka Libra required a minimum portafilter weight of 175 grams. Light portafilters and dosing cups therefore sometimes do not work.
- Continuous grinding without the weighing function is not easily possible. At least 175 grams of weight must still be on the fork. This contradicts logic. This type of grinding is triggered by pressing the two cup icons on the display. Other grinders like the Sette 270 Wi do this better.
- Some bottomless portafilters do not sit well in the fork.
The Modified Eureka Specialità with Scale
Strictly speaking, the Eureka Mignon Libra is a Eureka Mignon Specialità with a scale.
What's smart is that the grind adjustment of the Eureka Mignon XL is additionally used, thus improving one of the Specialità's major weaknesses. Otherwise, the Libra is a classic Specialità.
55mm burrs sit in a square aluminum housing. 12.4 cm width, 43 cm height, and a depth of 19.2 cm are reminiscent of the Mignon XL.
And otherwise, the Libra shows solid Specialità performance. At 79.8 decibels, it is still relatively quiet. The retention is 2.4 grams. With a grinding speed of 20.2 grams in 10 seconds, the grinder is in the better mid-range of home espresso grinders. The temperature rises from grind to grind, but remains in an acceptable range with an average of 36.1 degrees Celsius.
There is a ray of hope in terms of grind adjustment, as the Libra is equipped with the larger grind adjustment of the XL. This allows for a more precise adjustment of the grind. Nevertheless, in terms of adjustment, the grinder will never be among the best in its field, as even the larger wheel is too imprecise for that.
Most importantly: the espresso also tastes like the espresso from a Eureka Mignon Specialità. We drink a rounded, rather full-bodied espresso. The grinding mechanism of the Eureka Mignon Libra performs better with medium and darker espresso roasts.
Buying the Eureka Libra
The following specialist shops sell the Eureka Libra, and we recommend purchasing from these businesses. All offer the option to adjust the machine's offset.
Germany:
Austria:
We are looking for specialist partners for you who we know do good work and offer good service, and we are in close contact with the mentioned retailers. The links are so-called affiliate links. If you order via one of these links, you won't pay a cent more – but we will receive a small commission, which we invest directly in new test equipment.
We continue to search for competent partners in the DACH region for you.
A Good Scale with Problems
The Libra's scale works well. It can be calibrated and precisely set. We observe slight deviations from the target weight, which is related to the grinder's calibration. But the grinder precisely dispenses the desired amount of ground coffee into the portafilter from shot to shot.
Unfortunately, there is a problem. Although the portafilter shows the correct grammage, a few tenths of a gram are scattered around the grinder. The ground coffee does not aim precisely into the portafilter and scatters eagerly around it.
This is a typical problem with Eureka Mignon grinders, which is prevented in other models by tapping the portafilter during grinding. However, this procedure is not possible with the Libra because it cannot complete the weighing process.
This is not fully developed and is a consequence of equipping an existing grinder with a scale without adequately considering further adaptations. To cleanly fill various portafilters, an adjustable spout would be the solution.
Unfortunately, a calibration weight is not included. Even the significantly more expensive Mahlkönig E65s does not include a calibration weight.
A Dosing Ring as a Solution
A dosing ring, which is not included, provides a remedy. The Swiss importer of the grinder already pointed out a corresponding solution. Yes, that makes sense. Portafilters can be clamped in easily with a dosing ring and are then precisely ground. With a dosing ring, we could not detect any scattering around the grinder.
The dosing ring variant is a good workaround for a technical weakness of the Eureka Mignon Libra.
Possible shops that offer dosing rings:
Espresso Workflow with the Eureka Libra
A grinder with an integrated scale makes many things easier when preparing espresso. Espresso is a short, strong coffee drink with a coffee-to-water ratio typically ranging from 1:1.5 to 1:3. A popular ratio that tastes good to many coffee drinkers is 1:2.5.
For a double espresso, for example, 15 grams of coffee are ground to an espresso-fine consistency. The final result in the cup, with a ratio of 1:2.5, corresponds to two and a half times the quantity, i.e., 37.5 grams.
Classic espresso grinders are first set to the correct grind size. Then, the grinding time is determined by repeatedly grinding until the grinder dispenses the exact amount of ground coffee. This takes time and uses a lot of coffee.
It is not possible to set the grinding time before adjusting the grind size, as finer and coarser grind sizes take different amounts of time to grind, causing the dosing quantity to fluctuate.
A grinder with a scale makes constant manual weighing unnecessary. After clamping in the portafilter, the grinder tares the portafilter and grinds the exact amount of coffee into it.
Important: when adjusting the grind size, about 3 grams should still be ground at the new grind setting and not used, so that the retention is cleared. Only then will the result of the grind size adjustment be visible in the next extraction.
We have written an article about setting up specialty espresso here.
Conclusion on the Eureka Mignon Libra
The Eureka Mignon Libra without a dosing ring is not a fully developed grinder. It performs at the level of the structurally similar Eureka Mignon Specialità in the basic categories and is therefore good.
However, consistency and, above all, usability are limited to inadequate due to the scattering of ground coffee around the portafilter.
By using a dosing ring, consistency becomes very good and usability good. In this combination, the Eureka Mignon is a very good grinder with a scale, which offers an interesting simplification for home baristas in preparing espresso.
The ratio of water to coffee is crucial for the quality of espresso. Instead of having to re-weigh with an external scale, the home barista can now rely on the grinder.
With a dosing ring, the Eureka Mignon Libra is a very good espresso grinder for preparing espresso and cappuccino at home.
Helpful Links:
In Switzerland, the Libra is available, for example, at Quimbaya and at Kaffee-Erlebnis.
The links marked with an asterisk to Kai's Barista Legends are affiliate links to Amazon. You pay no more, but we receive a commission if a purchase is made via the link. This supports our work.
Update January 20, 2023: Eureka sent us the following message.
SPOILER ALERT: MIGNON LIBRA DOSING FUNNEL IS ALREADY AVAILABLE 😍😍😍
Dear Coffee Community and Kaffeemacher:innen followers, in consultation with Kaffeemacher:innen, we would like to add this short comment to provide you with complete information on the correct use of the Mignon Libra. In this context, we would like to emphasize that our research and development department has developed a dosing funnel specifically designed for the Mignon Libra fork to ensure the best possible results and avoid losing coffee when grinding extra large quantities. We recommend using this accessory for:
- > 8 grams for a single shot
- > 15 grams for a double shot
- 20 - 22 grams for a triple shot
You can receive the dosing funnel either already in the Mignon Libra box (when ordered as an option) or separately (as an accessory). Please inquire with your preferred retailer.
You can find it in chrome finish, in two possible diameters:
- 58.3 - 57 mm
- 54 - 53 mm (coming soon)
If you want to discover all the details, we provide a "How To Use" video.
By the way, we would like to point out that the Mignon Libra is already factory calibrated. If, unusually, there are still major deviations, you have the option to recalibrate the Libra yourself with a few simple steps. For more information, please contact us here or directly at EUREKA - contact. We are happy to help.
We would like to thank Kaffeemacher:innen for the great review and wish you all a contemplative and merry Christmas.
Eureka Team 😊
