The new Compak R120: a Gentle Giant in Coffee Grinds

(By Frans Goddijn and Jan van der Weel)

This week, after a three months delivery time, we picked up the Compak R120, a tall (77.5cm) heavy (37kg) new grinder.

Jan van der Weel helping with transport
Technical data:

Motor output: 1000 W
Revolutions per minute: 1400 rpm
Ø Burrs: 120 mm
Espresso point production: 1,5 Kg per minute
Hopper capacity: 2,2 Kg
Height x width x depth: 775 x 230 x 380 mm
Net weight: 37,08 kg 

I frequently hear from fellow coffee aficionados that their spouse thinks his grinder takes up a lot of space in her kitchen. This R120 is a wonderful remedy for such situations. Buy it, place it erect next to the allegedly "big" grinder and everyone will agree that seen in the right perspective, the old grinder was rather moderately proportioned, just big enough for a lady!
Who said the HG One was big? 
First impression: it's wonderful and very easy to prepare a delicious extraction with very little fuss. 

New body
Acording to Compak, the reason for the extra long delivery time was the development of a new metal body for the grinder. The new mold needed to be tested and signed off before they could cast the new body design. From pictures of the previous R120 I don't see any difference so it might be in the details.
[later note: Montse Ibern of Compak Spain wrote me to explain that the difference is in the tray at the foot of the grinder, which can be more easily brushed now to collect grinds that fall there.]
Jan, a tall man even for the Dutch, has no problem reaching for the hopper
The dealer, Van Pommeren in Utrecht, offered to season the burrs, putting a few kg's of beans through but we wanted to have the feel of the machine right from the very start.

It needs a 1 minute rest after grinding 2 non-stop minutes but I doubt we will ever really need 3Kg of espresso grinds immediately.

New burrs in 350 years
I will need new burrs after grinding 12,000 Kg of coffee and I calculated that at my current rate of preparing coffee, the first burr change will be 350 years from now. I could tell my children and ask them to remind their grandchildren but I'll probably have to attach a steel engraved plate to the bottom of the grinder to alert an owner in the far away future.

During our first testing immediately upon installing the grinder, we soon migrated from the IMS 18g filter basket to a lower dose Strada/VST 14g basket. We did this because there is so much "oomph" coming from the grinds already, a shot from 18g would be really loud in taste. As loud as the R120 bag shaker is in audio, but more about that later. This increased taste intensity is apparently caused by the combination of my LONDINIUM L1-P lever espresso machine which already delivers more "body" in the shot than my previous L1 machine of the same brand, and this new R120 grinder.

Extra complexity
Some darkly roasted beans that would taste just simply like "dark beans" before, now have a pleasant complexity and other beans from which I would expect a certain dryness or acidity can be extracted simply to avoid those elements with less grinder experimentation than I needed before.

Flow increase
The start of the extraction usually is slower than I was used to see but that is compensated towards the end when the flow is faster even though then the spring lever pushes less hard. This, I understand, is due to the excptional evenness in grind particle size.

I am baffled by the easy way it offers to prepare a delicious shot. For me this experience feels like years ago when I got my first a prime lens for the digital camera. Until then, I had enjoyed a very good lens but one that took its time to get focused. I could hear the little servo searching the proper focus point and making the best of it until I pressed the shutter release. Then when I got this costly lens, all of a sudden it was snap, with the half-push of a button the image was perfectly sharp and the parts outside the focal depth looked dreamily beautiful.

"So that's how they do it," I thought. Pros can own unbelievably better tools.

Much the same now with this grinder matching my L1-P. I still love the HG One and I will not forget how to prepare delicious shots with it, but with the R120 it's like cheating big time. An almost unfair advantage.

The big dial, tuning in to the optimal brew
Jan van der Weel, who helped me set up the grinder, directed and accumulated the measurements we did using the VST refractometer and VST syringe filters during the first afternoon.

This is his report:
After installing the Compak R120 grinder it was time for some serious testing. We started brewing lots of espresso to find out how this massive grinder performs. 

We used coffee from different roasters. One of the things we wanted to know is much we could extract from the beans without getting bitterness or other nasty tastes. Using the VST refractometer we got an insight in the extraction yield of the brewed coffees. We brewed, tasted and measured samples of 9 shots. Our aim was to get a better insight in the performance of the grinder and we would also get a documented first impression of the way this grinder affects flavour. 

For the first shots we used very fresh coffee from a roaster based in Utrecht. For every shot 18 grams was precisely dosed into the IMS B70 2T H24.5 M basket. The first thing we noticed after brewing was the clarity of the flavour. The taste was very transparent. There was however also a clear element of dryness. At first we thought that this might have been caused by over extraction but after measuring the brew we concluded that over extraction was not the cause. The VST app showed that about 18-18.25% of the grinds was extracted into the cup.

We wanted to know what would happen if we would extract more. Therefore we ground finer and used a higher brew ratio. We decided to use the VST 14 grams filter basket and a brew ratio of 1:2.4. This time we used coffee from an Amsterdam roastery. We brewed about 33.5 grams of coffee by using 14 grams of grounds. The shots were very clear again, flavours expressed themselves wonderfully. The highest extraction we could get from this coffee was 19.7 percent. We think it will be difficult to extract more from it. Maybe it’s possible to develop this bean a little further by a different roast profile. There was however still a little dryness in the taste. Was this caused by the coffee, grinder, extraction or brewing? Or was it caused by something else? Maybe it was caused by roasting? Matt Perger recently wrote at his blog that dryness can be caused by baking, meaning roasting at an increase in speed (temperature rise) after the first crack. We’re not sure about this, but it might be an explanation. 

In the third brewing session we used Burundi beans that were roasted a week before, on location. We used the same 14g VST basket and brew ratio (1:2.4). Two roasts were put to the test. One was slightly lighter than the other. After brewing and tasting we concluded that the shots we creamy, sweet and transparent. Both shots had a pleasant lingering aftertaste. The dryness was almost gone. The lighter roast was a little less sweet than the slightly darker roast. The extraction yield showed to be higher than our previous attempts. This higher extraction yield came with no negative side effects. We were able to extract 21.7% from the darker roast without getting any bitterness.
This was just a first try out of the Compak R120 in combination with the Londinium L1-P. More testing needs to be done to get a better insight into the performance of this grinder.

Even so, our first impression is that the Compak R120 seems to be very good tool for dissecting a roasted coffee. By using this grinder in combination with the VST refractometer you will know how far you will be able to extract a coffee. Over- and underdevelopment because of roasting will become very clear. The flavour of the coffee becomes very transparent. Every little flaw of the bean or roasting will reveal itself. This makes the Compak R120 an excellent tool for people who want to improve their roasting.
Burundi -> R120 -> Londinium L1-P -> cup

A detail of the parts view (previous R120 version)
From LOUD to quiet
In the top of the grinder, there's a separate motorized mechanism running a snare through the "throat" between grind chamber and chute to prevent any grinds from remaining behind and inside the chute there's a long metal spike to also counteract static electricity.

Under the hood, top of the R120 grinder
In the bottom there's a metal hammer "bag shaker" banging away at the tall chrome blade that can hold a bag to be filled. This ensures that no ball of coffee grinds can build up at the top of the bag and all grinds tumble down into the bag right away.

Foot view of the R120
This pushrod can be VERY loud. As if my neighbour is drilling a hole in his wall using his power hammer drill. On the inside of the grinder, this pushrod is rolling along a rubber puck that's attached off-center to the cam of the huge motor.

Roller pushrod and rubber oblong disc in the center
I will mostly just make myself an espresso and I expect to only fill a bag on occasion for friends. So the noisy bag shaker needed to go. With the help of Willi Egger, the friend who also built my elm wood HG One travel case, this proved easy enough:

So now we are all set to experiment some more! 

R120 next to the HG One


Populaire posts van deze blog

Tiny Cheap Fluid Bed Roaster by Tije and Jan

TC4+ boards and Arduino controlled roaster by Matthias Gerstgrasser

Time to PID a Pavoni