Compak F8 Grinder - In Depth Review

Commissioned Review

Espresso equipment seems to fall into 3 categories with some areas that cross over.   The beginner home user, the prosumer home user, and professional shop.  The Compak E8 is definitely designed for a professional shop or a serious home user with a bit of $$$ and wants an amazing statement piece next to their espresso machine on a bar without overhead cabinets.  

Unboxing this grinder, very simple packaging.  The top has a box with the hopper, instruction manual, and a few allen wrenches. Beneath, was the F8 nestled into some formed foam to protect this beast.  It weighs in at about 28.6 lbs.  I saw my UPS man lug it from the truck to the porch.  Still the box has carry handles, easy to grab and haul into the house.  

I wasn't sure what to think about this grinder prior to getting it.  I wanted to like it, a lot of people told me its great, the styling was attractive, the hopper design I personally think looks really cool and it is unique as well.   I just wasn't sure what could be all that much better than what I had used or how it might be as good or better than other in a similar caliber.  The Compak brand seems to have positive reviews, but never really has a cult following around them like some other brands.

Getting it out of the box, it was so amazing!  I immediately related to this grinder and knew why it is such a great piece of equipment.  The design was attractive and it is built like a tank! This thing is ready for some serious use in a serious coffee shop!

Overall, this thing is huge!  That is a good thing in my opinion, but definitely not for all.  For a shop its an awesome statement piece next to a fancy high end commercial two group machine.  I put this grinder into the pro category as it is more designed for commercial use with a very large bean hopper.  It could easily withstand use all day every day for years.

The hopper is quite large, it easily holds 4 lbs of beans, which is perfect for a shop where you don't want to be filling up the grinder all day long.   With a busy shop you will fill up here and there, but it won't be constant like some of the smaller hoppers.  The hopper is very well made, the base has a keyed locking mechanism that appears to be a machined piece of plastic.  The hopper cut off is the most amazing one I have ever seen.  A solid piece of metal that swings back and fourth, the usual is a cheap piece of plastic.  The hopper stays in place with a set screw once rotated into place.  Its easy to loosen the screw, but I doubt many people really will need to remove that often.   If you are thinking about this grinder for home use, they do sell a short hopper for about 100 bucks.  it has the same styling, and is about 1/4 the height.

The portafilter holder is awesome, it was probably the first feature I noticed once I unboxed the grinder.  It is a machined piece of metal that is built like a tank!   While adjustable, I can tell it is designed with the 58mm portafilter in mind.  That being said, a huge majority of the machines, particularly commercial machines are 58mm.  The portafilter easily props into place and stays without holding.  I don't think I would leave it there as if I were to bump it, it might fall out, but maybe not.   Its perfectly solid when you need it to be.  I prefer it over some of the other cradle style portafilter holders.  You can trigger the dose via a stainless button at the back of the portafilter cradle.   So a win/lose to the holder.  I have become accustomed to using a dosing funnel.  It contains my grounds to keep my counter top clean and allows for some WDT action.   Big difference, this thing grinds so fluffy and clean, I don't need a funnel!   In a coffee shop where one would never use a dosing funnel, this really makes grinding a dose and pulling a shot relatively mess free and very controlled!   With this grinder, the grounds are so amazing, id throw my dosing funnel in the trash.  There is no need.  WDT? maybe a single tap on your tamping mat, no need to toss these grounds around.   I will also note that it seems like new grinders or fresh burrs usually want to clump, not here, this thing just piled the fluffy grounds.  A second note, the first one or two grinds in the morning tend to be a bit messy.  I think the retained grounds tend to fly out of the chute vs fall out in a controlled manner.   

Adjusting the Portafilter holder

Finally getting it going, there is a 3 way switch, the middle is off, flip to the back and it turns the grinder on without the electronics, flip to the front and it turns the electronics on.  I am not quite sure why you would want to flip to the back other than for maintenance, there is no control, the grinder just runs.  

The display is great, it has 3 dose selections.  They are pre-set for 2, 4, and 6 seconds out of the box.  There is a Menu/OK button, manual grind button, and a back arrow for flipping through the displays.  The display itself shows which dose and the dose time.   So here's where I got a bit lost.  I did not read the instructions, well... because I don't like reading instructions.  I knew I would figure out how to change the dose time eventually.... I was wrong, I ended up googling it, so not overly intuitive.  That can be good or bad depending on your shop.  Its good if you don't want people fooling with the dose time, it could be a bit more work if you plan to adjust the time relatively frequently.  For me, I usually just adjust my grind size and not so much the dose time, so in a shop using the same bean it should not be a big issue.   All that being said, to change the dose time simply double click the dose number, then click the Menu/OK button.  At that point it puts you into a programming mode for that dose.   Use the #1 dose option to decrease time, and #3 done option to increase, kind of like a +/-.  The buttons change colors to make more intuitive, but still for a first time user you might say "what?".  Once set, click the Menu/OK button again. 

Compak F8 Espresso Grinder Functions from Barrett on Vimeo.

The grind adjustment is a side mounted step less adjustment knob.  It feels great and is pretty easy to use.  For me, on day 1 messing with the grind adjustment I was not quite sure what was going on.  I am used to adjusting a dial and it adjusts the grind.  This grinder is a bit different, there is a worm gear the adjust the burrs similar to many machines, but the increments are actually shown on the screen vs on a dial around the adjustment knob.  For a shop, if you don't want your baristas messing with your dialed in time/and grind setting, you can use an Allan wrench to lock the grind adjustment dial into place.  Honestly not a bad idea for a shop.  If anything it could help prevent the accidental adjustment of the setting.

Grind Adjustment from Barrett on Vimeo.

I finally got to pull some shots, holy smokes!   The grounds are amazing, it was like a cloud of espresso grounds coming out the chute into my portafilter.   Not having a clue where the grinder was set, or how quick it ground I selected dose number 2 which is a 4 second grind time.   It left a heap of grounds in my portafilter!   Way too much, but it was a nice stack that I was able to level off using my finger.  After figuring out that 2 seconds wasn't enough, I set the dose to 3 seconds which was perfect from a volume standpoint.  At this point I am not weighing out shots but simply seeing what's close.   The 3 second mark was near perfect for a 20g VST basket.   Noting this, this grinder grinds very fast.  My Super Jolly and Fausto take about 8 seconds to grind a dose, this is about 3 seconds.

Still playing with dose time and grind size, the shots were a bit too course in my initial tests, but dialing in the shots, they were looking and tasting great!

A few misc features.  I like the ground tray, it is built into the heavy base and has a plastic insert.  It seems less in the way than the thin and flat stainless style trays that lay on a counter top, especially for a shop atmosphere.  The sides are about an inch deep which is perfect to contain some spillage.  The front of the tray is open which could be nice if you just want to sweep the mess out into the trash vs remove the tray.   The tray works well, but I did notice a few grounds under the tray when I removed.   Putting the tray back in, it doesn't want to align perfectly at first, but once aligned will snap into place with ease.  


  • It grinds amazing, a huge step up from many traditional high end grinders such as a Mazzer Super Jolly.  Straight out of the box there was no clumping, it has such fluffy grounds.  Similarly little to no static.
  • It grinds very fast!  The large burrs allow a ton of grounds to come out the chute.  Very handy in a coffee shop where you want to streamline your brew process.
  • It looks amazing.  The styling looks great, the hopper is unique and elegant.  The base is polished and stands out great.  The ergonomics are great for a shop while retaining styling.
  • At first I was thinking it might be a con, but as I used the grind adjustment knob, having a number to follow on the display is much more accurate than a random knob adjustment on a traditional grinder.  This has a way to track it.  
  • For a pro grade grinder, it is relatively quiet.  I don't think you will even notice it in a busy coffee shop.


  • It might be too big for some people, particularly home users.  Still, this is more made for a shop, and would be awesome in any shop.
  • The first one to two grinds of the day which contain some retained grounds tend to be a bit messy for me.  Once you get into fresher beans it tended to fall perfectly into the portafilter mess free
  • For me, changing the settings for the dose time is awkward.  I wish they would have made it so that you could simply hold down the selected dose and adjust the time.  Not intuitive.    

Parting thoughts:   

I love this grinder, it is quite amazing and maybe even over looked in the Mahlkoning world.  Mahlkoning is an amazing grinder and I would easily put this up there along side it.  

Bonus: under the hood of the Compak F8 grinder

The adjustment knob turns this worm gear.  The worm gear turns the top burr.

The display shows how much the burrs have moved via this potentiometer.  As you then the adjustment know the screen displays how much the burr moved in +/-850 increments.  Very cool and less guessing than the traditional knob with no electronic measurement.  The arrow points to the electronics that tracks the burr.

The F8 has quite large 83mm burrs.  The surface area is much larger than the typical Mazzer sized burr that is on many machines.  It makes extremely fast work of grinding up coffee beans.

A top view of the chute

The electronics.  Should never see unless you need to replace the battery.   I think I need a new battery.  You will need a 2.5mm Allen wrench to remove the top plastic guard as well as the adjustment knob.  Quite simple, but should never need to do.

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