# Fines



## 4085 (Nov 23, 2012)

A lot of mention of this word recently, so, how about a totally un-scientific test? Grind 18 gms in your best way, sieve it and weigh the residue in the sieve. I guess we could all cheat and use a wide meshed sieve but whats the point? I think, the sieves with the plastic mesh or nylon...the cheap ones with the plastic handles, are seemingly similar in size.

Anyway, this is not obligatory and I am sure those that know will have advice/comments to make, so before I go running off to try it, any thoughts please?


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## Kyle548 (Jan 24, 2013)

It might be worth getting a dose of sieved coffee and a dose of, raw, so to speak, and then making a shot and comparing them.

Of course, I imagine flow rate will be pretty different between the two, so maybe not a perfect test.


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## dsc (Jun 7, 2013)

I've recently bought 6 different mesh sizes, all in stainless and sieved some coffee through them. Overall you'll get all sort of sizes in the grind, but it tends to be a bell curved distribution. Are we talking brewed grind or espresso?

Regards,

T.


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## MWJB (Feb 28, 2012)

Some things to bear in mind (gleaned from folk much cleverer than me)...

Setting a grinder finer increases the proportion of fines.

Roasting a bean darker increases the level of fines at that setting in that grinder.

Espresso grinds may be unsuitable for sieving (tiny bits sticking to bigger bits, rather than falling through the sieve)?

250um is typically used for drip brewed sifting, though Randy Pope went with a larger target size, but with less boulders, in an experiment at the NBC.

if you don't know the mesh size, how do you know what you are sifting out, fines or target size?

If you actually brew your fines (as Matt Perger suggests happens in EK-43 espresso) are they "fines" or just littler grinds?

Are your fines adversely affecting your brews/shots to a point that you notice? I have noticed that for a given extraction I get muddier flavours with a Porlex/Hario in a Clever, than with a Lido....but is that because the Porlex has more large particles over the average/target, rather than too many smaller particles (grinding 30g very fine in the Porlex/Hario is too much like punishment to explore this)? The Lido takes 3 times as long to hit sweet spot, grinding at espresso levels in the Rocky, takes longer to brew than the Lido. How does particle shape, distribution, sharpness of burrs affect steeping vs drip?

So can we even find a common definition of fines and are they always a bad thing?


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## dsc (Jun 7, 2013)

I always assumed fines are small grinds not sure what other definitions people have. I do agree that sieving espresso grind levels is a bit of a faff with variable results, see big discussion on HB about how it's a bad idea to sieve in regards to grinder particle distribution:

http://www.home-barista.com/grinders/coffee-particle-size-distribution-poor-mans-approach-t28894.html

I know the mesh sizes, but still the only info you get out of sieving is all that goes through is smaller than the mesh size and all that stays is bigger than the mesh size. Not a very accurate method if you ask me as it gives ranges rather that particular sizes and their amounts. I'm all for ranges (it would be mad to want precise sizes of all particles) assuming these are small, if you want that you need a lot of sieves and a lot of sieving.

I've had a brew out of the ZR-71, pour over, loads of fines as it's an espresso burr set. Tasted better than the Guatemala in espresso you need fines to brew properly me thinks, in pour over I also think you need grinds to slow the water drain, the only method where fines might be not needed is FP I'd say.

Regards,

T.


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## The Systemic Kid (Nov 23, 2012)

MWJB said:


> So can we even find a common definition of fines and are they always a bad thing?


Any particle smaller than 50 microns in diameter as particles that size don't contain any intact cells.


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## dsc (Jun 7, 2013)

Hmm, how would you separate such a size from the rest of the grind? Btw this is how stuff sticks:









Regards,

T.


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## The Systemic Kid (Nov 23, 2012)

Kyle548 said:


> It might be worth getting a dose of sieved coffee and a dose of, raw, so to speak, and then making a shot and comparing them.
> 
> Of course, I imagine flow rate will be pretty different between the two, so maybe not a perfect test.


Better test would be to grind a few grams more than your normal dose and sieve. Make a brew using your normal dose from the sieved grinds. Compare the result to your normal grind dose.


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## MWJB (Feb 28, 2012)

The Systemic Kid said:


> Any particle smaller than 50 microns in diameter as particles that size don't contain any intact cells.


Cheers, makes perfect sense. I had hoped to ponder that one little longer, oh well!  Thinking more for steeped, than drip/espresso, what if we brewed with all/mostly this size? I have never had Turkish coffee, but isn't the target size only around 100microns, wouldn't this imply a significant proportion of particle around 50microns?

I have a hunch (crackpot theory #374 in a never ending series) that large chunks may be more detrimental for steeped coffee, as long as you can separate the beverage from the fines. Just a hunch...


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## Kyle548 (Jan 24, 2013)

The Systemic Kid said:


> Better test would be to grind a few grams more than your normal dose and sieve. Make a brew using your normal dose from the sieved grinds. Compare the result to your normal grind dose.


To get the same flow rate your sieved dose would have to be a few grams higher than your normal dose.

The same dose made from sieved grounds would probably just piss though; assuming the same grind level.

If you changed the grind level, the test would be irrelevant though.


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## Charliej (Feb 25, 2012)

So to sum up so far, in some cases fines are fine.


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## Kyle548 (Jan 24, 2013)

Fines are good for espresso, not so great for brew methods such as pour over and probably make no difference to French-press if you don't agitate too much.

I don't see what all the hate for fines is about really....


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## The Systemic Kid (Nov 23, 2012)

Kyle548 said:


> I don't see what all the hate for fines is about really....


At medium/coarse grind settings, the amount of fines thrown up in a dose amount to between 2%-4% of the total dose. That isn't going to make a big difference but is one of several variables to bear in mind when trying to optimise extraction percentage.


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## dsc (Jun 7, 2013)

dsc said:


> in espresso you need fines to brew properly me thinks, in pour over I also think you need grinds to slow the water drain, the only method where fines might be not needed is FP I'd say.





Kyle548 said:


> not so great for brew methods such as pour over and probably make no difference to French-press if you don't agitate too much


In pour over fines will lower the rate it which the water passes through the coffee bed, thus making the contact time between water and coffee longer. In FP fines and generally smaller grinds will extract faster. At least that's my theory.

Regards,

T.


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## 4085 (Nov 23, 2012)

I am just learning pour over type drinks, and fines se em to play a part. I just thought a bit of unscientific harmless fun would be the order of the day!


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## The Systemic Kid (Nov 23, 2012)

dfk41 said:


> just thought a bit of unscientific harmless fun would be the order of the day!


- amongst us bunch of obsessionals, you must be joking David. Having said that, removing the fines this morning and doing everything else exactly the same caused the brew to give off loads of strawberry aroma as well as taste which didn't come through in yesterday's which included the fines ..... or maybe it was 'cos I was licking a strawberry Mivvi at the time!!


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## stub24 (Sep 22, 2013)

These talks of scientific tests always make me want to take some coffee into work, I work as an R&D chemist so have access to lots of fancy equiptment one of which is a laser diffractometer which can provide nice particle size distribution data and would easiliy be able to compare the level of fines in a sample. Shame I cant shove coffee through it!



> Any particle smaller than 50 microns in diameter as particles that size don't contain any intact cells.


Have to disagree with the above I'm afraid, the definition of fines is very subjective depending on the sample in question and also what do you mean by intact cells?


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## MWJB (Feb 28, 2012)

dsc said:


> In pour over fines will lower the rate it which the water passes through the coffee bed, thus making the contact time between water and coffee longer. In FP fines and generally smaller grinds will extract faster. At least that's my theory.
> 
> Regards,
> 
> T.


Smaller grinds (for a given grinder) may extract faster in a FP, but I'd be surprised if it was considerably faster for them to reach their maximum extraction than nominal grinds (erm, whatever they are)? Particles that are particularly large may not get up to maximum extraction (22-23%) before the coffee is too cold, maybe clamped at a lower yield? This ext. level assumes no agitation other than wetting & pouring off the bed at brew end, rather than draining though it (e.g. Clever, or pouring beverage & slurry into a filter cone).

Maybe I'll try a Clever ground at "0" on the Lido tomorrow...


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## dsc (Jun 7, 2013)

I'll be now experimenting with brewed coffee from the ZR-71, might be good to check how well the conical work for pour over / FP. I guess in the end it all evens out in the FP, as you say large ones underextract, small ones come close to overextracting.

Regards,

T.


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## The Systemic Kid (Nov 23, 2012)

stub24 said:


> Have to disagree with the above I'm afraid, the definition of fines is very subjective depending on the sample in question and also what do you mean by intact cells?


Agree it's subjective but the definition isn't mine - it's Scott Rao's '....therefore, as a reasonable standard, I will consider particles smaller than 50 microns in diameter to be fines' (Everything but Espresso.


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## dsc (Jun 7, 2013)

stub24 said:


> These talks of scientific tests always make me want to take some coffee into work, I work as an R&D chemist so have access to lots of fancy equiptment one of which is a laser diffractometer which can provide nice particle size distribution data and would easiliy be able to compare the level of fines in a sample. Shame I cant shove coffee through it!


Ahhh! such a shame, I'd be packing up some samples for postage straight away









Regards,

T.


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## stub24 (Sep 22, 2013)

dsc said:


> Ahhh! such a shame, I'd be packing up some samples for postage straight away
> 
> 
> 
> ...


We do sometimes use an outside analytical service for some of our work but at £100 a sample its expensive!




The Systemic Kid said:


> Agree it's subjective but the definition isn't mine - it's Scott Rao's '....therefore, as a reasonable standard, I will consider particles smaller than 50 microns in diameter to be fines' (Everything but Espresso.


Fair enough, I suppose ground coffee for brew methods apart from espresso is the subject.


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## MWJB (Feb 28, 2012)

MWJB said:


> Smaller grinds (for a given grinder) may extract faster in a FP, but I'd be surprised if it was considerably faster for them to reach their maximum extraction than nominal grinds (erm, whatever they are)? Particles that are particularly large may not get up to maximum extraction (22-23%) before the coffee is too cold, maybe clamped at a lower yield? This ext. level assumes no agitation other than wetting & pouring off the bed at brew end, rather than draining though it (e.g. Clever, or pouring beverage & slurry into a filter cone).
> 
> Maybe I'll try a Clever ground at "0" on the Lido tomorrow...


20mins steep ground at "0"...should have gone longer (was at ~30min Lido set to 0.67), flattened off as it cooled. Thicker mouthfeel than yesterday, but don't know whether the finer grind is doing this or the change in bean.


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## garydyke1 (Mar 9, 2011)

I witnessed an Uber grinder in action yesterday , at setting 7 (whatever that means) for chemex and cupping.

The fines! shocking


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## The Systemic Kid (Nov 23, 2012)

C'mon Gary, out the grinder.


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## The Systemic Kid (Nov 23, 2012)

Filtered the Chemex dose again this morning - about 3grms of fines produced. Resultant dose brewed out at 18.7% and gave one of the best cups of brewed coffee I've had which confirms my theory that I have been conditioned to veer towards body at the expense of flavour clarity. Today's brew, surprisingly, didn't feel lacking in mouthfeel either.


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