Power Freak wrote:On the retention rate: I'm basically down to "zero" now (as in I put 15.0g in and I get 15.0g out). Occasionally I'll get a 0.1g and very rarely 0.2g but not had more than that for a long time.

The things that seem to make a difference:

- Season the burrs well. If you've less than 5kg (minimum) through the grinder I'd wait a bit more
- Bolting the thing down helps a lot
- RDT is essential
- Grind as slow as you can stand. Let it stall every 1/4 turn or less, it's a bit annoying and slow but it definitely retains less with light roasts that way for me
- Once you've "finished" grinding fully open and fully close the burrs while spinning the handle - some grinds seem to catch on the burr teeth (I'm guessing) and opening and closing the burrs can dislodge them, the grinds should "fall" out rather than actually grinding the bean at this point so don't worry about creating boulders/fines

Hi there,

I'm with you in all points,
additionally after grinding maybe someone wants to try sliding a longer cable tie through the chute,completely through the chamber,one side in,other side out.
Kind regards,Thomas

Interesting idea with cable tie, I am using tea pot brush and it scratching the inner side of burr cover plastic...

New idea I tried this morning: grinding "backwards" slows the feed of beans into the burrs which makes it easier to maintain a lower speed which means less static, less retention and fewer fines.

I'm using light roasts, at one point I sent a video to Barb and she said the beans were too hard (I was able to grind backwards but not forwards, forwards would jam, I've got it bolted to a chopping board)...Barb said grinding backwards is easier because the burr teeth are less "aggressive" backwards...quote from email: "the burrs are slightly less aggressive in the 'left hand' direction, because in the left direction (counter clock wise) there is a leading slope to some of the teeth, but in the clock-wise direction those teeth are less leading-edge sloped, more vertical, and are more 'grabby'.

With my light roasts, I'm grinding either at the second or third most fine setting, and getting about 3-4 grams retention, I'm using RDT...if I wipe out the chute with a brush I get about 1g of true fines (ie dust like), then by opening up to the coarsest setting and grinding, I get about another gram of huge chunks (bigger than boulders)...then I vaccuum out the rest both via the chute and from the bean "hopper"

I have done complete disassembly and reassembly, not just deep cleaning...there were still chunks of beans in between the burrs when I took it fully apart, and coffee stuck between the teeth that I had to pick out with a tooth pick.

When I have ground coarse I was getting a lot less retention.

I think in the videos when Doug is getting almost no retention and then when opens up for deep cleaning there is "nothing there, I know there's no coffee in there", he is probably using a darker roast that shatters more easily and has less fines that are easily vacuumed out?

Please see the photos from disassembly here (unfortunately I forgot to take photos of the burrs when I took them out to show how much had accumulated in there): https://1drv.ms/a/s!AvfGVoSnpXdZ3EXSm6zjBfYkNNSf

Things to note:
-I had a lot of grinds in places they shouldn't have been (eg in the gear box), perhaps it was from too aggressive compressed air?
-lots of fines around the grind chamber
-you can't see it very well but lots of coffee stuck in the burrs

I've only had less than 1kg go through the grinder, and probably at the time I took it apart, maybe only 250grams.

In any case, I can see myself doing fully disassembly regularly and will take photos of the burrs next time.

Does breaking in the burrs result in less retention because the grinding quality improves, or just that the spaces where retention can occur get filled with coffee? In my case, I'm probably getting quite a lot of the coffee out through brushing and vacuuming...

bytheway wrote:I'm using light roasts, at one point I sent a video to Barb and she said the beans were too hard (I was able to grind backwards but not forwards, forwards would jam, I've got it bolted to a chopping board)...Barb said grinding backwards is easier because the burr teeth are less "aggressive" backwards...quote from email: "the burrs are slightly less aggressive in the 'left hand' direction, because in the left direction (counter clock wise) there is a leading slope to some of the teeth, but in the clock-wise direction those teeth are less leading-edge sloped, more vertical, and are more 'grabby'.

With my light roasts, I'm grinding either at the second or third most fine setting, and getting about 3-4 grams retention, I'm using RDT...if I wipe out the chute with a brush I get about 1g of true fines (ie dust like), then by opening up to the coarsest setting and grinding, I get about another gram of huge chunks (bigger than boulders)...then I vaccuum out the rest both via the chute and from the bean "hopper"

I have done complete disassembly and reassembly, not just deep cleaning...there were still chunks of beans in between the burrs when I took it fully apart, and coffee stuck between the teeth that I had to pick out with a tooth pick.

When I have ground coarse I was getting a lot less retention.

I think in the videos when Doug is getting almost no retention and then when opens up for deep cleaning there is "nothing there, I know there's no coffee in there", he is probably using a darker roast that shatters more easily and has less fines that are easily vacuumed out?

Please see the photos from disassembly here (unfortunately I forgot to take photos of the burrs when I took them out to show how much had accumulated in there): https://1drv.ms/f/s!AvfGVoSnpXdZ3DDqJCYiiHBUD6D7

Things to note:
-I had a lot of grinds in places they shouldn't have been (eg in the gear box), perhaps it was from too aggressive compressed air?
-lots of fines around the grind chamber
-you can't see it very well but lots of coffee stuck in the burrs

I've only had less than 1kg go through the grinder, and probably at the time I took it apart, maybe only 250grams.

In any case, I can see myself doing fully disassembly regularly and will take photos of the burrs next time.

Does breaking in the burrs result in less retention because the grinding quality improves, or just that the spaces where retention can occur get filled with coffee? In my case, I'm probably getting quite a lot of the coffee out through brushing and vacuuming...

+1

bytheway wrote: Does breaking in the burrs result in less retention because the grinding quality improves, or just that the spaces where retention can occur get filled with coffee? In my case, I'm probably getting quite a lot of the coffee out through brushing and vacuuming...

Ben, curious what you think so far about the cup quality using your normal kit?

I've been playing around a lot with my V60 method recently so I'm a bit all over the place.

I'm not sure what I think about using the Melodrip...sometimes I like it, sometimes not.

I had an EK43 aligned using the Titus tool that I just sold a few weeks ago. At this early stage I can't say that the Apex is a downgrade on the EK43 (which is a good sign for the Apex), but I'll know better in a couple of months.

The EK43 was a lot less trouble though: zero retention with RDT, not needing to vacuum it out, no hand cranking obviously...so the Apex is going to have to be better than the EK43 to stop me getting something like a Titus grinder or Monolith in the future...

Hank, what are your thoughts compared to your bigger grinders (monolith flat and Tanzania)??

I don't have everything in the same place, so I can't really say one way or the other. And usually use an older Lido 2 in the morning or my Lido 1 in Taiwan. Actually the comparison I'd like to see is the Apex vs Fuji R220. OE brought out the Apex without knowing for sure how it would fit into the current array of hand coffee grinders.

bytheway wrote: I've only had less than 1kg go through the grinder, and probably at the time I took it apart, maybe only 250grams.

That's not nearly enough coffee, these are some big old burrs. Try and get some stales or cheap non-drinking coffee to pass through. My retention went to near zero just after approx the 5kg mark, I was never at 3-4g retention though that just seems crazy high.

I don't agree with Barb saying the beans are too hard, I'm currently grinding a nordic roast Ethiopian with zero issues and I don't think you could find many beans that are harder (unless you're roasting yourself to really really light levels)