User experience - Niche Duo 83mm flat burr grinder - Page 14

Grinders are one of the keys to exceptional espresso. Discuss them here.
tiji78
Posts: 20
Joined: 6 months ago

#131: Post by tiji78 »

guelfo83 wrote:...in the medium roast range... Today, I used 18.5gr of freshly roasted coffee with a grind size of 3.
considering that Duo burrs are given 1-20 for espresso, from my understanding 3 is definitely a grind size for turkish coffee, not espresso. I grind medium at 10-11 for 17-18g baskets with 1:2-2.5 ratio output. I also grind italian dark roast blends around 11-12 to get a perfect Italian shot. at start I tried finer around 5-7, it just slows the extraction and makes the shot awfully bitter. It can behave different with different coffees though.
guelfo83 wrote: This keeps happening with all coffees, regardless of the coffee I use. Also, the grinder needs to be set at very low sizes for medium roast hence it won't be able to grind light roasted coffees that require grinding even finer. Do you have any advice?
I do not understand how you can have so much retention. your burrs must be very sticky and covered with fat... even with dark roasts, mine holds a maximum of 0.1-0.2 sometimes, that can simply be pulled out using a small silicon blower (which by the way also prevent popcorning)

I would advice to try a good cleaning of all the parts and maybe zeroing your burrs again. This is also not normal to me that you have to grind at 3 to pull a decent regular espresso shots out of 18g of beans.

malling
Posts: 2851
Joined: 13 years ago

#132: Post by malling »

Retention depends on the humidity is my experience the lower humidity the higher the retention mine goes for almost nothing to about 0,4g. I stopped using RDT very early on because it really didn't do any noticeable effect most days.

3 is not turkish I'm almost down there with Weber Unibasket 16g basket on a 14g dose with some very light stuff. But you should definitely be plus 10 with medium roasted coffee with a 18g dose if zero is around the 0 mark.

The chance is it's poorly zeroed that really would not be a first, or it's really poorly aligned

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GregoryJ
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#133: Post by GregoryJ »

malling wrote:But you should definitely be plus 10 with medium roasted coffee with a 18g dose if zero is around the 0 mark.

The chance is it's poorly zeroed that really would not be a first, or it's really poorly aligned
The burr chirp is around -10 on the Niche Duo, if you calibrate it per Niche's instructions. Maybe I misunderstood your comment about "zero is around the 0 mark". Are you saying your burrs chirp or touch at 0?

malling
Posts: 2851
Joined: 13 years ago

#134: Post by malling »

Zero point (= where the burrs touch/chirp) is meant to be at zero if you watch the zeroing instructions of the official instructions video, this is also the standard procedure across most espresso grinders (or one notch off). Light burr lock is around -10 to -15 on most Niche Duo grinders (depending on alignment)

If you make zero so it's at -10 then you will likely end with using the start of the grind adjustments scale.

The only grinder I ever seen advertised to not have burr touch one mark off zero/one on the scale is the Fellow Ode, where the official is 4 notch off. All other grinders are zeroed so you get the touch at lowest settings or an equivalent of one notch beyond the scale. Why because this will deliver the greatest amount of adjustment on the scale, with a light your usually near touch point especially with more unimodal style burrs, those it's important for lighter roast always to have touch points at zero/one or an equivalent of one off.

tompoland
Posts: 268
Joined: 3 years ago

#135: Post by tompoland »

I'd love to know what @DavecUK thinks.

My two bobs worth: sounds like the burrs are not aligned.

Zeroing will obviously effect where you are on the dial and it sounds like your burrs are not zeroed. That just means you may need to be at e.g. minus 5 on the dial for a light roast but your primary issue is consistency. I doubt that its a tamping issue but a video of your puck prep and the pour using a bottomless portafilter basket would help enormously with diagnosis.

I read somewhere about a simple test for alignment. The theory is (someone please correct me!) is that you grind as fine as you can (close to chirp) and pop the grinds into a saucer. Gently press your finger or thumb into the bed of grinds and remove it. If you see a perfect thumb print, nice an even across the print, then the burrs are probably aligned quite well. As mentioned, please someone with more knoledge of this technique, post about your experience, thanks.
A little obsessed.

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GregoryJ
Posts: 1063
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#136: Post by GregoryJ »

malling wrote:Zero point (= where the burrs touch/chirp) is meant to be at zero if you watch the zeroing instructions of the official instructions video, this is also the standard procedure across most espresso grinders (or one notch off). Light burr lock is around -10 to -15 on most Niche Duo grinders (depending on alignment)
Ah you're right, sorry about that. I forgot they chirp around 0 and I just did the calibration a couple weeks ago :oops:

Jonk
Posts: 2117
Joined: 4 years ago

#137: Post by Jonk »

tompoland wrote:If you see a perfect thumb print, nice an even across the print, then the burrs are probably aligned quite well.
Someone's pulling your leg. At best you can guesstimate that it'll grind fine enough for espresso if you can see a thumbprint.

Does anyone know what the mechanism inside the Impress looks like? Does it really ensure a 10kg tamp?

tompoland
Posts: 268
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#138: Post by tompoland »

Maybe, but one of the leg pullers was Jonathon Gagnes in his book "The Physics of Filter Coffee" page 59 :D

A little obsessed.

malling
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#139: Post by malling replying to tompoland »

But it doesn't tell you how good aligned it is just that it's good enough to pull a shot and decently zeroed, if it cannot then either burr are incapable or it's incorrect aligned or zeroed.

But if you have two that you can make a fingerprint it won't really say which is the better aligned of the two.

I'm not going into the whole marker thing because it's largely unreliable and only really partially show how it performs without beans.

Jonk
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Joined: 4 years ago

#140: Post by Jonk »

It's a great book, but you need to take that little section for it's face value. A fingerprint is not a lot better, relatively speaking, to measuring things with feets and thumbs. Taken to the extreme, a cheap ceramic grinder with an axle that wobbles several mm for a pour over setting can grind fine enough if adjusted to the touchpoint to hold an imprint.