Rather than cluttering the "V60" thread, here are some links to Kruve sifting results, feel free to ask any questions if anything isn't clear. Can Gencer has some Kruve data here that's easy to highlight & drop in/out plots for comparison (by clicking, or double clicking on the results you want to highlight/eliminate). https://cangencer.github.io/cumulative.html https://cangencer.github.io/noncumulative.html

Here are also a few results with ASTM 600 & 1180 sieves. [URL=https://i.imgur.com/Sx0FuGD.png][IMG]https://i.imgur.com/Sx0FuGD.png[/IMG][/URL] Points to note are that as you go coarser with the same grinder, the % captured between the sieves decreases. In that repect Feld, Niche & Wilfa flat are not different enough to be viewed as different. The only one that stands out is the Porlex (but this still makes tasty brews when dialled in...if you can tolerate the extremely slow laborious grinding).

A cautionary tale regarding muddling Kruve & "microns" (ASTM/ISO/Tyler). This is not a determination that 700 & 1600 Kruve give similar results as 600um & 1180um, but just to show Kruve & "microns" are not interchangeable... [URL=https://i.imgur.com/IcXyQS0.png][IMG]https://i.imgur.com/IcXyQS0.png[/IMG][/URL]

Hi @"MWJB"#139, I have recently started brewing coffee using fresh light roasted beans and I have learnt a lot by scanning all your posts. First of all, thanks a lot for all the information shared! My grinder is a Niche Zero. I mainly use Clever Dripper, Aeropress and V60 02, planning to buy a Kalita Wave 185. I have a few questions that I hope to learn from you: 1. How big of impact does the filter have? I am using Kalita 103 filter for Clever Dripper, single original filter for Aeropress and original filter for V60 02. 2. In your [Grind references sheet](https://docs.google.com/spreadsheets/d/1p-SFk1gUI_KtBNcdvdGjcptQeRhZZNwHq6RlKfVtbAI/edit#gid=1832218036), the [Kalita Wave 185 (13.5:224, 25g bloom) recipe](https://docs.google.com/spreadsheets/d/1p-SFk1gUI_KtBNcdvdGjcptQeRhZZNwHq6RlKfVtbAI/edit#gid=651659669&range=A17:AT17) has a noticeably high average score (8.17), I am wondering what makes it so good compare other brew methods like v60? Also, what do you mean by 'shake' in this recipe? I am trying to learn 4 recipes from your sheets: 1. [Kalita Wave 185 (13.5:224, 25g bloom)](https://docs.google.com/spreadsheets/d/1p-SFk1gUI_KtBNcdvdGjcptQeRhZZNwHq6RlKfVtbAI/edit#gid=651659669&range=A17:AT17) 2. [Hario V60 02 (18:270, no stir at bloom)](https://docs.google.com/spreadsheets/d/1p-SFk1gUI_KtBNcdvdGjcptQeRhZZNwHq6RlKfVtbAI/edit#gid=88025033&range=A10:AT10) 3. [Aeropress](https://docs.google.com/spreadsheets/d/1p-SFk1gUI_KtBNcdvdGjcptQeRhZZNwHq6RlKfVtbAI/edit#gid=1832218036&range=A9:AT9) 4. [Clever Dripper (fast)](https://docs.google.com/spreadsheets/d/1p-SFk1gUI_KtBNcdvdGjcptQeRhZZNwHq6RlKfVtbAI/edit#gid=1483272121&range=A9:AQ9) I know this might be too much to ask but is there any chance that you can share the Niche Zero grind reference settings for these four recipes. Or do you recommend me to get a Kruve so that I can calibrate my grinder? Thanks again!

@"JJJJJamie"#p31489 I don't like Chemex white papers for filter brewing (but I do like them for polishing immersion brews, or for Clever). I use the white Kalita papers (101 & 155/185), Rombouts/Filtropa for truncated cones (Melitta style/Clever). I didn't know there were paper options other than original for Aeropress...I think I probably have enough original AP papers to last me the rest of my days!😀 If you notice a consistent, negative difference with a certain paper, then certainly think about using something else. Kalita 185, 13.5:224, 25g bloom, 8.17 score - I wouldn't read too much into that, a lucky run of coffees when doing those brews? I got the same score with V60 01 bloom & 35g every 20s with a Rhino grinder, and even got an average of 8.00 in a test with a Swan blade grinder. Brewer & grinder are not going to be driving those differences. I don't have an exact equivalent setting for the Niche at 12% 400 Kruve. or 29% 600um ASTM, for the Kalita recipe. I'd rather come up with a different recipe for the Kalita, then you can use the same grind for all 4 recipes. Say 20g/20s in 10sec pours to 220g? I'll give it a go when my next bag arrives. I would be around 93 on the Niche for Hario V60 02 (18:270g), maybe use the same grind for Aeropress (try knocking 15s of the brew time?) & Clever recipes (Clever needed to be a tad finer than what I used anyway). Kruve seem to be changing the stock fitment sieves from time to time, but yes, this would be a useful, if rarely used, tool. I could sift some more samples if you could only get a 500 as the nearest.

Here's the "shake" with the Kalita 185... https://www.youtube.com/watch?v=qkQTo1Fw0MY&t=41s

@"MWJB"#p31540 Thanks a lot for the reply! I just finished a brewing strictly following your Aeropress recipe and my partner is extremely happy with the result. :) I am trying to develop my tasting skill for coffee and build a score sheet for my brew methods, but currently I can only taste sourness and bitterness in my coffee… To dial in a new bean, my understanding based on the posts in this forum is: control all the other variables and only change the grind size based on the taste of coffee. If changing grind size still cannot give me a good result, in what order do you suggest changing other variables like dose-water ratio, bloom time, etc. > @"MWJB"#p31540 I’ll give it a go when my next bag arrives. Thanks again, and I am looking forward to it. > @"MWJB"#p31540 I would be around 93 on the Niche for Hario V60 02 (18:270g) In your recipes, what does 93 mean for Niche Zero? It shows only from 0-50 on the machine. > @"MWJB"#p31540 Kruve seem to be changing the stock fitment sieves from time to time, but yes, this would be a useful, if rarely used, tool. I could sift some more samples if you could only get a 500 as the nearest. My Kruve sifter is on the way, I think this is the only way to calibrate grind settings. Mine comes with 300, 500, 800, 1100, and 1400μm sieves. > @"MWJB"#p31541 Here’s the “shake” with the Kalita 185… The videos are super helpful, subscribed!

> @"JJJJJamie"#p31545 I am trying to develop my tasting skill for coffee and build a score sheet for my brew methods, but currently I can only taste sourness and bitterness in my coffee… > > To dial in a new bean, my understanding based on the posts in this forum is: control all the other variables and only change the grind size based on the taste of coffee. If changing grind size still cannot give me a good result, in what order do you suggest changing other variables like dose-water ratio, bloom time, etc. I don't dial in beans, I dial in the method. Brewed coffee isn't that finicky. I don't make changes based on one bean/coffee (unless truly awful and due to something other than a bad roast). I make a few coffees at one recipe, then think about whether they have a common fault & what I might do to correct it. For pourover/drip, I might change the amount of water poured for a 1 cup brew by +/- 10g (just in the last pulse) to see if less more extraction improves it. If a few brews of the same recipe seem under, I'll tighten up the grind for the next few. I don't think bloom time is critical enough to have a big impact, other than if grinding very fine you might bloom longer, if you are coarse & pouring in a lot of pulses you don't really need to anything different for the first pour/bloom.

@"MWJB"#p31558 Thank you! I didn't know I need to grind so coarse…

Sifting brewed coffee grinds

MWJB

JJJJJamie In your recipes, what does 93 mean for Niche Zero? It shows only from 0-50 on the machine.

Set your calibrated grinder to 50, make a second grind marker with tape/tippex/point at “0”. This second mark is now in effect “50”, to get to 93 turn your new marker to 43. 43+50=93.

JJJJJamie

MWJB Thank you! I didn’t know I need to grind so coarse…

MWJB

JJJJJamie My Kruve sifter is on the way, I think this is the only way to calibrate grind settings. Mine comes with 300, 500, 800, 1100, and 1400μm sieves.

Use 500 & 1400

PortafilterProcrastinator

Thank you for starting this thread @MWJB , a good idea to separate from the v60 discussion.

So there seem to be two main advantages/ goals to sifting. 1 is being able to objectively compare grind size and ‘callibrate’ two (or more) different grinders for the same brew method. 2 is being able to compare grind size distribution.

One of my comments on the v60 thread was about understanding the principle of these comparisons. It is easy to follow an instruction and get a result, but it is another thing to understand the ‘why’. This is less relevant for the calibration of grinders, but when then looking at grind size distribution and discussing in terms of standard deviations the more one understands the fundamental principles the more one will get out of it and be able to objectively interpret and use that data more.

I don’t know if this is along the same lines as your example of kruve vs ASTM, but I seems easy to interpret that as the two different sifting scales correlating - I.e. x Kruve = y ASTM - without understanding the principles behind it.

I am pretty certain I am going to get a kruve, but it’ll have to be in the new year.

@JJJJJamie - where did you order your kruve from? Will be interested to hear how you get on with it.

You can buy the 400 separately, but you might not need to depending on use.

JJJJJamie

PortafilterProcrastinator I live in the UK and ordered from their official website, free shipping for order above $99, I think. I didn’t see the individual 400 sieve; they only sell the whole set.

If you are interested in the particle distribution of ground coffee, this is a very interesting paper. @MWJB I think you might find the paper interesting as well.

MWJB

JJJJJamie If you are interested in the particle distribution of ground coffee, this is a very interesting paper.

The premise of the paper you link to was known to be false prior to the paper being written (it was already known that grinding too fine decreased extraction, rather than increased it). In a previous paper some of the authors were advocating finer grinds & freezing grinds to achieve this…funny how that fell by the wayside so quickly. Sifting espresso grinds is not practical and few people have access to laser diffraction, though Erol Uman was contacted by a member on CFUK and gave prices for samples to be analysed.

I’m more interested in what people can do, see & measure in their own homes, with grinders they use (not just EK-43s - the only grinder analysed in both studies).

JJJJJamie

MWJB That’s very interesting.

In an espresso setting, with other variables (tamp force, dose) controlled, based on the Ergun equation, a finer grind will yield higher pressure drop (Pin - Pout). Using same amount of water, I thought higher pressure drop means higher contact time of water and coffee, therefore higher extraction yield.

But the Ergun equation is assuming a uniform grind size I believe. What is the definition of ‘too fine’ and why it decreases extraction? Could you please send me the discussion or paper suggest that grinding too fine decreased extraction? I am really interested into this.

JJJJJamie

MWJB In the pour over setting, I think the ‘too fine’ coffee particles will just clog the filter, thus lower extraction? But does the same theory (too fine = lower extraction) apply to espresso extraction?

MWJB

JJJJJamie I’m not really prepared to talk about espresso grinding in this thread, it’s essentially off topic. But this effect has been observed in real life by many people who measured their extractions. A lack of permeability in the bed is the likely cause (“partially clogged flow”). Think about an espresso ground so fine you only get a few grams out, there is little liquid in the cup and it’s extremely unlikely there is enough to hit a typical extraction, there’s obviously a tipping point where this occurs, even when you can still achieve target weight.

No coffee grind distributions are “uniform”, or they all are. Even grinders with tight distributions have a large range of particle sizes.

MWJB

JJJJJamie MWJB In the pour over setting, I think the ‘too fine’ coffee particles will just clog the filter, thus lower extraction?

Long before too fine a grind (not particles, the grind setting as a whole, because that is all we can adjust) starts to under-extract, brews at a reasonable extraction will maybe become overly silty, then brews will over-extract. Only when you are absurdly fine will brews channel and extraction significantly drop…there will be clear clues in the progression before you get to this stage.

That said, drip brewing has wide range of usable grinds and adjusting pour speed can often normalise extractions for the same brew size & ratio, within that range.

When a recipe is dialled in to a grind setting, then maybe some of those brews will either under-extract, or over-extract, but not both. With 99% of coffees (at a suitable roast level) you won’t swing from one to the other.

PortafilterProcrastinator

@MWJB I was lucky enough to be gifted a kruve sifter, so I’m going to be getting stuck in over the next couple of weeks.

My set doesn’t have a 400, it goes from 300 to 500.

I’ll start with v60, but also want to see how it works for CCD/ Moka Pot.

Have you found what you consider to be the ‘floor’ in terms of grind size before the results become unreliable?

Also, do you recommend having scales that weigh to 0.01g? I’d rather not be buying more, but I also want my results to be accurate and useable.

Your advice is always appreciated and hopefully I’ll be able to feed in a bit with my results.

MWJB

PortafilterProcrastinator I use 0.01g scales but you can sift 10-20g so give it a go with 0.1g (check they are not really 0.3-0.4g scales that read to a decimal place, by seeing how sensitive they are bean by bean).

Use 500 Kruve in the bottom, biggest you have in the top. Shake side to side for 2min, with frequent taps to the side & downward.

The finest grinds I have used for brewed were just under 25% passing through 400, So I’d guesstimate around 20% at 500.

Sure, let me know how you get on.

MWJB

MWJB So I’d guesstimate around 20% at 500.

Oops, got that back to front, more like 25-30% at 500.

PortafilterProcrastinator

MWJB Thanks Mark.

I’ll let you know how I get on with the 500 for v60.

Plan is to clean out the niche and sift 93, then I’ll see where I’m at on the F47. Then I’ll see whether running a few kgs through changes anything.

MWJB

PortafilterProcrastinator I’ll let you know how I get on with the 500 for v60.

Just to be sure, you’re just using the 500 to see what the grind setting is, rather than discarding any grinds.

PortafilterProcrastinator

MWJB Just the grind setting yes.

Once I’m familiar with the process then I will also note down distribution, to compare my niche to F47.

PortafilterProcrastinator

So I finally found time to do my first sift. Potentially interesting results - or I did something wrong.

19.9g @ 93 on Niche (50+43) | 500Kruve at the bottom | 1400Kruve at the top

1.6g 8% passed through 500Kruve into the base

11.7g 58.8% caught by 500Kruve

6.7g 33.7% caught by 1400Kruve

Rounding errors I assume due to scales accuracy.

@MWJB Does the % through 500Kruve seem low for that grind? (I ask this acknowledging there isn’t really a right answer)

I wasn’t aggressive with the sifting, but I also wasn’t gentle by any stretch. Side to side, back and forth, taps side and top.

I will do anther sift next week and also do one with the F47.

MWJB

Your results look a little different to what I just got, the under 500 does seem a tad low:
Under 500 = 2.42g (12%)
Over 500 under 1400 = 12.13g (61% - the difference between 59% & 61% is not alarming)
Over 1400 = 5.29g (27%)

I’d expect 8-9% at 400Kruve, you should get noticeably more at 500.

Did you shake for 2 minutes?
Did you check that your scales go up & down in 0.1g increments?
If so, it could just be calibration difference between our grinders.

Most importantly, how is the coffee tasting at this setting?

PortafilterProcrastinator

MWJB Thanks.

Shook for 2mins with taps on the side and top. I’ll try again and be more vigorous!

My scales are Timemore Black Mirror Nano - from a couple of tests they look to be 0.1g at that weight (I note on the bottom it says they go to 0.2g at a certain point). I can already feel the itch for 0.01g scales.

I used some old beans this time, just to try it out, so didn’t brew with it, but I will next time and feed back.

MWJB

PortafilterProcrastinator OK cool, but like I said, the sifting could be in line and a difference in grinder relative setting be the answer, so sure, do a sanity check but don’t get too hung up on grinder setting number & % matching exactly.

I tend to dial in a regime, then when happy with that, sift a sample.