Has the ultimate espresso grinder finally arrived? Our Coffee Specialist (and chemical engineer) Adam Carr is on site to give his insight into the latest grinder technology announced in Milan. So if you’re ready to get technical, let’s dive in the deep end…
Mazzer Robur S Kold electronic
Mazzer impressed me this year with their latest rendition of the Mazzer S Kold. This model boasts:
- Reduction of grind retention by 52%
- Double fan cooling system
- Belt drive motor at low RPM (420-520rpm)
- Larger diameter conical burrs
- Introduction of a declumping system
- Electronic tracking of grinding data
In this case, 3 of the innovations make undeniable sense.
First: a double fan cooling system located close to the burrs of the grinder dissipates heat throughout service.
Second: the belt drive motor isolates conductive heat generated by the driving motor.
Third: The motor drives the burrs at low rpm, reducing heat generated by shear and particle-particle friction.
Finally, larger burrs mean a larger surface for grinding, resulting in lower shear contact between ground coffee particles, and reduced heat generation through friction.
Ultimately, if these modifications result in a cooler grind, the resulting coffee particles will have lost fewer volatiles through the grinder, producing a better tasting brew.
The declumping system is a larger series of crossbars that are placed at the chute of the grinder. The design facilitates reduced retention and highly efficient declumping. Similarly, Mazzer have improved the layout of the chute and housing to reduce retention of the grinds. This means that a higher proportion of fresh coffee will flow into the portafilter.
Mazzer have also implemented a preset system. In this case, 3 grind presets can be loaded, facilitating grinding for different brewing applications. It can also be used to change grinder settings through the course of the day – enabling a rapid ‘on the fly’ adjustment as demand at the café increases.
On the electronic side of life, Mazzer have been able to implement a tracking system on their grinder – displaying total grinds completed, grams dosed, and over what period. This helps with keeping ahead of service intervals – knowing when to change the burrs ahead of time on a per kg basis.
Victoria Arduino have released their Mythos 2 grinder. This new model adds some impressive new technology, including:
Variable speed motor.
This is an interesting feature. The speed of the motor can be modified to between 600rpm and 1200rpm. According to Arduino, this allows for fine tuning coffee flavor by adjusting the ground coffee particle size distribution.
One might argue that fine tuning between origins or blends may not be as dramatic as changing between 600 and 1200rpm (perhaps modifying from 650 to 700 may suffice). Nor does the grind range span the current offerings from other manufacturers (for reference, the EK43 has 1740rpm, and the anfim is 450rpm (similar to the Mazzers), indicating that we may not be able to replicate the flavor of an EK or an Anfim/Mazzer in the Mythos.
Of course, the proof will be in the testing of the machine – taking a coffee and modifying motor speed while keeping espresso recipes consistent. We’re certainly looking forward to getting our hands on one to test out!
This follows on from the gravimetric technology (scales), available in the Black Eagle and the La Marzocco ABR espresso machines.
Typically when dosing from a grinder, a timer is used to automate the dispensing process. However, using time to control dose can lead to some errors as ambient temperature, humidity and café peak periods change throughout the course of a day.
Dosing by weight is potentially a powerful tool when combined with the new ‘Clima Pro 2.0’ technology. The expectation here is that even if bean properties change slightly, the dose in the portafilter remains constant. Of course, the shape and size distribution may change based on humidity, but it’s certainly a fantastic attempt at helping baristas in a café environment.
Dual fan cooling and Clima Pro 2.0
In the new design, a cooling system has been placed on top of a heating system. This sounds a little strange on first thought (like turning heating on one side of your car because the air conditioning on the other side is too cold), however there are some benefits.
First, the primary objective of the fan is to cool the motor housing, lowering the operating temperature of the system at busy times. The second is to be able to lower the control temperature of the Clima-Pro heating system – effectively widening the range of control options. So the introduction of fan cooling is fantastic, but it will be interesting to see at café level how the cooling system performs during busy times.
Wider titanium burrs
I’m a fan of wider burrs, so the introduction of a wider set on the Mythos is a good thing. Wider burrs mean reduced burr wear over time, improved heat dissipation and a reduction in blade heat-up.
In conclusion, the Mythos 2 is a sophisticated piece of kit. However, this increased sophistication could also mean more expensive and more frequent servicing. Further, I’m not yet fully convinced as to how effective these innovations will be in the real-world café. Some features that improve tunability can also overcomplicate the serving of coffee, complicating an already complicated business. The proof will be in the flavor, so testing on these kits before buying is essential!
This grinder has two particularly interesting features.
This grinder weighs the dose of ground coffee at the hopper, rather than at the portafilter. This is an effective means of controlling grind dose, though there will be some loss in the grinding chamber, leading to some error. The demonstration we got, though, was certainly no less accurate than a dialed-in timed doser, and is a lot more simple to keep track of.
This technology relies on an algorithm that adjusts the dose output based on grind modification. In other words, when a grind is made finer, the grinder adjusts the objective mass of coffee grinds, thus (in theory) facilitating rapid ‘on the fly’ adjustments by the Barista.
The grinder also features titanium blades, which is of course good for food applications.
The only issue I take with the grinder is on the algorithm used for grinder adjustments. The auto-adjustment may be perfect for one cafe, or completely off at another. As such, the barista will need to override the control system (which the grinder does have the capability of doing). The only way to check this, however, is to repeatedly pull test shot, as one would with a traditional grinder. How far off the grinder is, we can’t say – we certainly need to do some tests!
San Remo Revo (& Revo 3) prototype
While at HOST, we were treated to a private demonstration of the new San Remo Revo/Revo 3. San Remo have come to the table with a ‘Grinder to end all Grinders’. This machine has had significant thought poured into all the variables that could affect grinding.
I’ve attempted to summarise some of the many design features:
- Vertical blades, for direct drop-down grinding
- Diamond like blades for grinding. These have a black coating that are super hard, reducing blade wear rates, and keeping grinds consistent for longer life
- Optional direct drop-down (think EK43 grinder) options, and hopper-fed grinding in the same unit
- Auger feed from the hopper. In this case, no vibration in the hopper is experienced, but beans are instead pushed into the hopper
- Isolating ‘valve’-type interlock system for precise delivery of feed beans
- Gravimetric dosing
- 3-hopper feed system – enabling 3 blends/single origins/decaf to be delivered in the same platform
All of these design features add up to one impressive grinder that does the work of 2, or even three grinders.
Gravimetric dosing is certainly the technology most leading grinder manufacturers are leading with. How essential is this? Well, even if it’s no worse than timed grinders in terms of repeatability, it certainly lets you know how accurate you are every time, rather than having to move the portafilter to a separate scale. So, in terms of practicality, the concept works well, and should help workflow. How durable the systems are is yet to be seen.
My favorite two grinders of the show are 1) the Mazzer Robur S Kold (for the practical chilling system) and the Fiorenzato KGi for the uncomplicated dosing design.
Mazzer does not yet have a gravimetric dosing system, but they certainly have improved a great deal over the older Roburs. Both systems should be able to handle high throughput well, based on the technology implemented, and would be good choices at any café.
I’d be very keen to put this grinder head-to head with the Mythos, Mythos 2, Fiorenzata XGi and Anfim’s latest offerings. Ultimately, selection of grinders comes down to flavor and usability. If a grinder can’t do well on both of these criteria, it’s not doing its job. These are things you can only test when the grinder is ‘in your hands’. As such, we will hopefully get these grinders in the lab for testing very soon, and taste and test the differences between them.
If you have questions about the latest espresso grinders or are interested in learning more, you can drop us a line, visit us at our Training Centre or join us at one of our Barista Training Programs.