Whenever Eureka brings another "Mignon" espresso grinder onto the market, my reflexive response is: "Not again?" After all, there are now more than a dozen espresso grinders in the Mignon family that are similar in construction.
However, the Eureka Mignon Libra at least partially breaks the mold. It is the first Mignon with an integrated scale. This means the quantity of ground coffee is no longer time-controlled, but instead stops once the target weight in the portafilter is reached. That is genius, if it works.
In this review, you will find out how well the Eureka Mignon Libra weighs, grinds, and fits into the workflow alongside your home espresso machine. We also provide tips for a good workflow and assess the grinder's strengths and weaknesses.
There is now another version of the Eureka Libra, namely the Eureka Libra 65 All Purpose. We have tested this grinder as well.
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 improves them with the addition of a scale.
- The Libra's scale works well. It can be calibrated and set precisely.
- However, the grounds chute does not target the portafilter perfectly, which is why coffee is scattered around the grinder during the grinding process.
- This is a typical problem with Eureka Mignon grinders, which is prevented in other models by tapping the portafilter during grinding.
- This procedure is not possible with the Libra, however, because it would interrupt the weighing process.
- A dosing ring provides a remedy, though it is not included in the delivery. With a dosing ring, the grinder is a good choice. Without one, it is a problematic case. Eureka now offers 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 weak point. However, it is available, e.g., from Kai from Barista Legends*, also stylishly in wood from Etsy*, or from Wiedemann at Stoll*.
- In order to tare and therefore be able to grind, our Eureka Libra required a minimum weight of 175 grams for the portafilter. Lightweight portafilters and dosing cups therefore do not work in some cases.
- Continuous grinding without the weighing function is not easily possible. For this to work, there must always be at least 175 grams of weight on the fork. This goes against logic. This type of grinding is triggered by pressing both cup icons on the display. Other grinders like the Sette 270 Wi handle this better.
- In some cases, bottomless portafilters do not hold well in the fork.
The converted Eureka Specialità with a scale
Strictly speaking, the Eureka Mignon Libra is a Eureka Mignon Specialità with a scale.
It is smart that the grind adjustment of the Eureka Mignon XL is also used, thus improving one of the Specialità's greater weaknesses. Otherwise, the Libra is a classic Specialità.
55mm grinding discs are housed in a square aluminum case. 12.4 cm wide, 43 cm high, and 19.2 cm deep, it is reminiscent of the Mignon XL.
And apart from that, the Libra demonstrates solid Specialità performance. At 79.8 decibels, it is still relatively quiet. The retention is 2.4 grams. With a speed of 20.2 grams of grounds in 10 seconds, the grinder is in the better middle range of home espresso grinders. The temperature rises from one grind to the next but remains in an acceptable range at an average of 36.1 degrees Celsius.
Regarding grind adjustment, there is a glimmer of hope because the Libra is equipped with the larger grind adjustment dial of the XL. This allows for more precise grind adjustment. Nevertheless, the grinder will never be one of the best in its class when it comes to settings; the larger wheel is still too imprecise for that.
The most important thing: the espresso also tastes like the espresso from a Eureka Mignon Specialità. We are drinking a balanced, rather full-bodied espresso. The Eureka Mignon Libra's grinder has its strengths more with medium and dark espresso roasts.
Buying the Eureka Libra
The following specialty stores sell the Eureka Libra, and we can recommend purchasing from these companies. They all offer the option to adjust the machine's offset.
Germany:
Austria:
We are searching for specialty partners for you whom we know provide good work and good service, and we are in close contact with the mentioned retailers. These links are so-called commission links. If you order via one of these links, you won't pay a cent more – however, we receive a small commission, which we invest directly in new test equipment.
We continue to look 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 set precisely. We receive slight deviations from the target weight, which, however, has to do with the grinder's calibration. But the grinder grinds the desired amount of coffee grounds into the portafilter precisely from shot to shot.
Unfortunately, there is a problem. Although the portafilter has the correct weight, a few tenths of a gram are scattered around the grinder. The grounds chute does not target the portafilter accurately and busily scatters grounds all around it.
This is a typical problem of Eureka Mignon grinders, which is prevented in other models by tapping the portafilter during grinding. This procedure is not possible with the Libra, however, because it cannot finish the weighing process if you do so.
This is not fully developed and is the result of an existing grinder having been equipped with a scale, without sufficient consideration for further adjustments. To fill different portafilters cleanly, an adjustable chute would be the solution.
Unfortunately, a calibration weight is not included. However, a calibration weight is not included with the much more expensive Mahlkönig E65s either.
A dosing ring as a solution
A dosing ring provides a remedy, though it is not included in the delivery. The Swiss importer of the grinder had already pointed out a corresponding solution. Yes, that makes sense. Portafilters can be inserted without any problems even with a dosing ring and are then ground precisely. With a dosing ring, we did not notice any scattering around the grinder.
The version with a dosing ring 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 beverage with a coffee-to-water ratio of usually 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 espresso fineness. At a ratio of 1:2.5, the end result in the cup is two and a half times the amount, i.e., 37.5 grams.
Classic espresso grinders are first set to the correct grind size. Subsequently, the grinding time is determined by repeatedly grinding until the grinder dispenses the exact grinding amount. That takes time and uses up a lot of coffee.
It is not possible to determine the grinding time before setting the grind size, because finer and coarser grind sizes grind for different lengths of time, causing the dosage amount to fluctuate.
A grinder with a scale makes constant manual weighing unnecessary. After inserting the portafilter, the grinder tares the portafilter and grinds the exact amount of coffee into it.
Important: When adjusting the grind size, you should still grind through approx. 3 grams at the new setting and not use it, so that the retention is cleared. Only then will the result of the grind adjustment show 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 is not a fully developed grinder without a dosing ring. It performs in the basic categories at the level of the structurally similar Eureka Mignon Specialità and is therefore good.
However, the consistency and, above all, the usability are limited to poor due to the scattering of the coffee grounds around the portafilter.
By using a dosing ring, the consistency becomes very good and the usability good. In this combination, the Eureka Mignon is a very good grinder with a scale that allows for an interesting facilitation of espresso preparation for home baristas.
The ratio of water to coffee is a decisive factor in the quality of the espresso during preparation. 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, e.g., at Quimbaya and Kaffee-Erlebnis.
The links to Kai's Barista Legends marked with an asterisk are commission links to Amazon. You do not pay 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 the Kaffeemacher:innen, we would like to add this short comment to give you the full information on the correct use of the Mignon Libra. In this context, we would like to emphasize that our R&D department has developed a dosing funnel designed specifically for the Mignon Libra fork to ensure the best possible results without losing any coffee when grinding extra large quantities. We recommend using this accessory for:
- > 8 grams for single shot
- > 15 grams for double shot
- 20 - 22 grams for the 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 dealer of choice.
You can find it in a chrome finish, in two possible diameters:
- 58.3 - 57 mm
- 54 - 53 mm (available soon)
If you want to discover all the details, we provide you with a “How To Use” video.
By the way, we would like to point out that the Mignon Libra is already calibrated from the factory. If there should still be unusually large deviations, you have the option to recalibrate the Libra yourself in a few simple steps. For further information, please contact us here or directly at EUREKA - contact. We are happy to support you.
At this point, we would like to thank the Kaffeemacher:innen for the great review and wish you all a contemplative and Merry Christmas.
Eureka Team 😊
