Inconsistent shot weight with newly received Niche Zero - Page 4

Grinders are one of the keys to exceptional espresso. Discuss them here.
liquidmetal

Postby liquidmetal » Mar 22, 2019, 4:29 pm

DaveC wrote:I watched the Video, the two coffees looked quite different before grinding....were they the same bean and batch? You even remarked the second was chaffy...


Same exact coffee out of the same bag that I tested with the Sette. I'll run a shot through the Sette to confirm that the coffee is okay.

Yes, this coffee has been chaffy the entire time.

Edit: Pulled the shot, it was the same as when I pulled it before on the Sette, ran just fine at 20.1:35g.

Here are the grind output from the Sette. Markedly less chaffy...

Image

rittem1

Postby rittem1 » Mar 22, 2019, 4:32 pm

Is this the only coffee you have tried? Have you tried a forgiving blend? Have you taken it apart completely down to the sweeper arm, given it a really good cleaning?

I wasn't able to watch your video on my phone but with such a huge discrepancy between outputs of the same bean prepped the same way I can't help but think something is off with your grinder.

Facetime with Martin...
LMWDP #517

liquidmetal

Postby liquidmetal » replying to rittem1 » Mar 22, 2019, 4:37 pm

Only coffee thus far, but it does just fine on the Sette, so I'd expect the NZ to be at least as good, right?

DaveC

Postby DaveC » Mar 22, 2019, 4:41 pm

I've never experienced a difference like that with the same coffee and prep....not even close...the most I see is a few g.

liquidmetal

Postby liquidmetal » replying to DaveC » Mar 22, 2019, 4:42 pm

How unfortunate for me. Oh well, I guess I will need to talk to Martin and straighten this out, show him all the evidence and see what he wants to do...

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drgary
Team HB

Postby drgary » replying to liquidmetal » Mar 22, 2019, 4:46 pm

Yes! I'm closing this thread briefly to discourage people from chasing this before you have that conversation. Please report back to us what you've found.

Added: Matt will be talking with Martin on Monday.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

samuellaw178
Team HB

Postby samuellaw178 » Mar 22, 2019, 5:27 pm

Just my 2 cent below, not 100% sure it can fully explain the discrepancy in shot weight but it should help reduce the gap.

To me it looked like your shot wasn't extracting evenly and it was preferentially flowing from the edges. At the end of the extraction, you can see that brown liquid was still (or just started to) coming through the middle while the rim was already blonde. This would be considered channeling and might explain the higher shot weight in the first shot. So your first shot had edge-channeling (more water channel through the puck) and there is less channeling in the second shot.

Image

Based on my own experience, if you eliminate the edge channeling in the first shot, the flow will be much slower (wouldn't be surprised if it looks like the second shot). So I definitely think that you need to adjust your grind setting coarser, and work on evening out the coffee bed by being more aggressive on the WDT end.

When I do WDT, I always have this imaginary picture where the coffee bed consists of flour and sugar (two different particles), and that I am trying to mix them well to get a homogenous bed.

This short video illustrates the point above:
https://www.instagram.com/p/BKBKuuJjHa4/?hl=en

Have a look at 6:20 here for a WDT example, notice how much the coffee was moved/mixed within the basket.


The Niche will require a more thorough WDT (than the Sette) due to it being a single doser, so what worked on the Sette might not directly be translatable to the Niche.

Good luck and hope you get it solved!

liquidmetal

Postby liquidmetal » Mar 25, 2019, 10:45 am

Talked to Martin this morning.

He' s understandably looking for more data. He suggested pulling 3 shots, grinding a little extra from each dose, spooning it out, and saving it to compare.

Results (at about a 15 setting):
(in/out)g
20.0g/54.7g
Image
20g/15g
Image
20g/52.5g
Image


How do these grinds look to people?

These were performed with the same process as before: a little shake in the cup, quick stir, invert + dump into PF, better stir, tamp, pull.

20g decent basket, decent self leveling tamper, Lucca m58.
Red bird ethiopian hambela from same 5lb batch (which I am dumping into the sink at an alarming rate).

I sent these results to him, I am waiting for feedback.

My next idea is to switch back to the stock baskets and see if that helps at all...

wai2cool4u

Postby wai2cool4u » Mar 25, 2019, 11:01 am

it's difficult to eye ball grind distribution by just looking at a couple of pictures online.

the only way to know for sure if your particle size is all over the place is to use a set of kruve sifters. But they aren't cheap and probably not worth it for just diagnosing a grinder.

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drgary
Team HB

Postby drgary » Mar 25, 2019, 12:11 pm

The second photo is a duplicate of the first.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!