Variation in shot times

dfk41

One of my basic rules, is repeatability of process. My grinder is a 350 gm hopper fed Eureka Atom 75. I definitely find as the beans empty, the shot times change so I always try to keep it topped up. I am using a cheap blended bean that I really enjoy. But, I can pull a shot 18gm in 34 out over 32 seconds or so and the next one I pull half an hour later with nothing changed in the approach, can take 14 seconds longer!

I have noticed this over the months. My own thoughts are that it must be the bean as nothing else makes sense. I watched Hoffmans dial in video using a Mythos One and even though the burr adjuster directly links to the motor so you are raising a hefty lump up and down, it still reacts well to very small incremental changes. Whereas on my grinder which works on a different basis for adjustments, the incremental changes seem to be far far greater.

Does anyone have any thoughts?

Adrianmsmith

dfk41 I definitely find as the beans empty, the shot times change so I always try to keep it topped up.

I agree with this. Maybe the mini g has a smaller diameter throat or is more forgiving….

I’m ok up to this level. The shot I just weighed will be great BUT if i don’t add more this next shot will popcorn and will be variable.

Id estimate nearly 2 shots in the system at that point (21g shots)

LMSC

MediumRoastSteam It’s likely retention (due to grinds going stale overnight), making the shot quicker. Even if it’s 3g - that’s 16.6% of the overall dose.

I haven’t read the thread in entirety. Dfk, in his opening post, mentioned

dfk41 But, I can pull a shot 18gm in 34 out over 32 seconds or so and the next one I pull half an hour later with nothing changed in the approach, can take 14 seconds longer!

As we know, sale beans/ground would produce a faster shot. Longer shot time doesn’t fit here, does it? :-)

Tal

Machine temp?

Retention? (First shot has retained grinds from overnight?)

dfk41

Tal Nope. This is not back to back but with a rest. The grinder weighs out the desired weight. I have not checked retention since I first bought it but when I did, it was reasonably low for a hopper system. My own thoughts were the blend has 4 constituents. Let us just say it is 30% for the 3 main beans and 10% Robusta. Once mixed together then there must be a reasonable chance if you separated the beans out then what you are about to grind followed that pattern. What if it was 50%, 25%, 15%, 10%. What would a scoop of beans then look like? Could this explain the shot time variation? OR am I wide of the mark?

MediumRoastSteam

I’m with Tal.

It’s likely retention (due to grinds going stale overnight), making the shot quicker. Even if it’s 3g - that’s 16.6% of the overall dose.

@dfk41 - does the same happen when you use the Niche? That would be a good test - e.g.: To use the Niche, as it’s virtually no retention over a few days and observe if the same thing happens.

dfk41

MediumRoastSteam Good thought! I will try that. I will also set button one to blip a couple of gms out before first shot. That said, I am comparing the second shot of the day to the first, or the third to the second so the overnight scenario does not really fit

delta76

Do you have a blower? try to blow up the chute and some ground can fall down. I was surprised how much it could retain there with my Specialta. Even 1gr can make a big difference.

dfk41

delta76 I do have a blower thing and I also have a blower hopper, but I did not really use it as it meant running the bean hopper right down to virtually empty and that does seem to affect shot time

delta76

dfk41 what I meant was blowing up the chute, not blowing down from the hopper.

dfk41

delta76 Yep, I follow. I was just saying that I have both. I am going to spend a few days purging before I go onto the blower up the shute!

Adrianmsmith

delta76 what I meant was blowing up the chute, not blowing down from the hopper.

I am confused about the aim of this practice. Is it to blow coffee back into the burrs For some reason or in fact, will it blow coffee back into the burrs?

MediumRoastSteam

dfk41 - any updates?

Clodius

@dfk41 now you understand why I wanted the Niche Zero? Much more consistent shots now. I also got a mini blower (which is a bit annoying for a few reasons). There’s another topic where we discussed extensively the same issue called Inconsistent Shot Times.

Adrianmsmith

Clodius now you understand why I wanted the Niche Zero?

Not really. Please explain further….

All of the grinders I have and have had apart from the sage smart grinder Pro and the dreaded df83 Mark 2. Are great and work as I expected when used as intended and correctly.

I currently use:
mazzer philos
mazzer mini g

Kafatek flat max 2 (Which will be for sale when I can finally get around to sorting out an advert. I’m taking some pictures. I’m told I have to reduce grinder quantity!!)

Craig lyn hg-1 prime

Niche zero Which will most likely be used for decaf. This is my second niece zero.

Kinu classic m47 Which will mainly be for the nights away with the coffee Jack 2. If it ever arrives!!

All work great as intended. I do not purge anything from the mini. G. Day to day I purge around 4 g If I miss a day shot one and shot two in the morning are the same.

The Weber key grinder was good but has to be used with rdt. Otherwise static retention is a nightmare. Funny how the unpaid influencers do not mention this. Oh, are there any unpaid influencers

The niche duo was great and was only sold to make way to try others

The t64 had SSP burrs. Enough said. it made good coffee.

The df-83 Mark II basically garbage . Shot to shot Consistency was non-existent. And felt like it had been engineered by a 5-year-old on his first lathe.

I have many times states my case in the past for single dose grinding. That was mainly based on my experience with the sage smart grinder Pro and I thought all my Christmases had come when I read about the niche zero which I promptly purchased and loved. Was sold to make way for others.

I can also state a case for hopper grinding, especially if you are a family that uses it most days unlike me, who works away from home frequently but I’m still finding it great

The grind by weight feature of the mini g and also the atom W is great.

@dfk41 I have several times now, Check the mini g by pulling two shots in the morning. Straight off and my taste buds cannot distinguish the two. I can after a night away from home so therefore I do purge after a night away

delta76

Adrianmsmith some coffee ground stuck in the chute. I unintentionally blew up the chute and to my surprise a lump of coffee ground fall down. Been doing that ever since. You don’t blow the ground back to between the burrs but rather just “unstuck” them.

Clodius

@Adrianmsmith I had the Eureka Mignon Silenzio moded for SD with a blower and a tilted base (plus shimmed/aligned burrs) and, you can see in the other thread, the yield varied between shots by 10g+. Ever since I got the Niche Zero the variance is 2-3g, less now with the blower. There’s another topic annoying thing about the blower is that the silicone top is very flexible and my fingers stick in and by using the palm of my hand it seems to move the dial slightly.

Clodius

@Adrianmsmith I had the Eureka Mignon Silenzio moded for SD with a blower and a tilted base (plus shimmed/aligned burrs) and, you can see in the other thread, the yield varied between shots by 10g+. Ever since I got the Niche Zero the variance is 2-3g, less now with the blower. The annoying thing about the blower for NZ is that the silicone top is very flexible and my fingers stick in and by using the palm of my hand it seems to move the dial slightly.

dfk41

MediumRoastSteam YEs, a little. I decided to spend a few days looking at the various aspects of shot preparation. My first move was to make sure the 350gm hopper does not fall below ⅔ rds full and that definitely has an effect. The next step will be checking the exit chute for retention. I have various small bristle type cleaners that I will try before the blower. But, I need to do each step for a few days, so will update as I go

Tal

LMSC

it would if the first shot of the day runs fast due to previous days grinds? then the shot 30mins later has reasonably fresh grinds exchanged thus takes longer?

LMSC

Tal hmm, interesting. God, I am old for all these. 😅😂

What I am unable to correlate is the initial shot - almost 1:2 - taking 32s vs the next taking 14s extra. Either the retention is negligible or the ground is really fine. I am assuming the grind size setting hasn’t changed.

Perhaps, @dfk41 may clarify if “18gm in 34 out over 32 seconds” is always an example first shot. :-)