Controlled Grind

[Laurentius]

52 minutes ago, Deephaven said:

First time in this whole thread you used the word excess.  I was never referring to excess.  

 

This is pure neenerism.  I also never said "remove all the fines" or "no fines at all".  And where in this discussion, pray tell, did you allow that your grinder could throw too many?   How would you know without screening?

 

Obviously, a little knowledge and very expensive coffee tools are dangerous things.

[cdh]

I've never noticed an "excess bitterness" problem that can be attributed to the grind.  The only value in a highly precise grinder I see is getting a highly finnicky espresso machine to pull a good shot.  I'd imagine that the engineering that goes into $$$ grinders is pointed toward people who spend $$$ on espresso machines.  I'd imagine that some fines are there by design, as getting an espresso puck that both flows and provides the right resistance is a macro version of a geometric packing problem, and a certain % of fines is needed in the output to reach a satisfactory solution.  If you really hate bitter coffee, perhaps check your beans and your roast... there's a lot more bitter flavor coming from those than from the way you grind it.. 

[Laurentius]

43 minutes ago, cdh said:

there's a lot more bitter flavor coming from those than from the way you grind it.. 

 

Care to offer any substantiation?

[cdh]

Why would I bother?  You're unsatisfiable.   Go on believing as you wish.  I'm sure that you'll argue dark roasted robusta beans are no  more bitter by their nature regardless of grind, with no substantiation of your own.  Nothing I can do to change your mind. You need to take your certainty and find an investor or two and build the better mousetrap.  

Edited September 2, 2023 by cdh (log)

[Laurentius]

56 minutes ago, cdh said:

Why would I bother?  You're unsatisfiable.   Go on believing as you wish.  I'm sure that you'll argue dark roasted robusta beans are no  more bitter by their nature regardless of grind, with no substantiation of your own.  Nothing I can do to change your mind. You need to take your certainty and find an investor or two and build the better mousetrap.  

It was your certitude, not certainty, I was questioning.

 

Certainly, there are multiple variables that can affect bitterness.  One is clearly overextraction, which is related to particle size and time under temperature.

 

You seem to say that there are other variables more important to creating bitterness than particle size in a given brew.  I'm still interested in evidence to substantiate this claim. 

[cdh]

You seem to be mistaking this forum for a free scientific research service. If you want to pull apart all of the chemical causes of bitterness in brewed coffee, I'd find a food chemistry PhD program and apply... you've got the makings for quite a thesis if nobody has done it before.  And if buried in the stacks there is already a paper or 4  on the subject, then you've got the "substantiation" that you want.  You're not going to get it here.

[cdh]

You want quantitative substantiation?  OK.  Devise a quantitative and reproducible measure of bitterness that more people than you agree on and can implement.  Once you have that in hand, then we can perhaps interrogate your priors, e.g. "fines cause bitterness through over extraction, bitterness is bad, so fines must not be produced by coffee grinders. "  It will be interesting to see whether your numbers match up with your intuitions when you're doing a blind tasting of coffees brewed.  While you're devising that metric, get yourself a finely calibrated set of sieves so we can home in on what fines are too fine.   

[Laurentius]

Here's an interesting review of the Kruve screening product.  

 

Note that the amount of fines wasn't a lot different from the $5,000 grinder than it was from the $50 model.

[donk79]

On 9/7/2023 at 4:18 PM, Laurentius said:

Here's an interesting review of the Kruve screening product.  

 

Note that the amount of fines wasn't a lot different from the $5,000 grinder than it was from the $50 model.

I've been sorely tempted by the Kruve.  If I ever see one at a yard sale, I'll snap it up in a hurry!

[Laurentius]

9 minutes ago, donk79 said:

I've been sorely tempted by the Kruve.  If I ever see one at a yard sale, I'll snap it up in a hurry!

 

Me, too.  They're somewhat pricey to start with, and downright expensive if you want all the grades of screens.

 

I may go with a few of the old school scientific sifters if I can decide on the sizes. 

[paulraphael]

The assumption used to be that the best coffee (espresso or brewed) would come from a perfectly uniform grind. This idea persisted because there was no accurate way to measure grind distribution, and very few people who cared enough to figure it out.

 

Now the coffee science community has the drive and the budget, and all kinds of tools, including laser interferometry and statistical image analysis. One of the first things these newly-equipped, over-caffeinated scientists did was measure the grind distribution from the most respected and beloved high-end grinders. They did not find what they expected. In all cases they found a widely ranging particle distribution, with a peak at the selected grind size, but a slope in the histogram extending far in both directions—toward fines and boulders. And in grinders with certain bur designs, they discovered what they call bimodal distribution—2 peaks, indicating high quantities of grinds at two different sizes, along with the same slope into boulders and fines.

 

The conclusions to be drawn from this are complex and evolving. The especially tricky part has been trying to map these various distributions to predictable flavor profiles. The only thing that really holds up from the conventional wisdom is that the good grinders do produce a tighter distribution than bad grinders. But none produce a very tight distribution.

 

TL;DR: There are more things in heaven and earth and your coffee cup, Horatio, than is dreamt of in your philosophy. 

[scubadoo97]

My Mazzer Mini grinder is still running strong.  Still grinding home roasted beans every day