nickw wrote:Hi Sam, so many things I can respond too. And I have this bad problem with trying to be thorough.

Haha, it's a good problem to have!

nickw wrote: In regards to "Conical (burr) flavor", I think we should be careful when we say "conical burr flavor" or "flat burr flavor". Otherwise we may end up mis-associating results with burr type rather than the resulting grind distribution.

I suspect you're right, but it's hard for me to put it that way because what I can taste in front of me is the flavor, not the grind distribution (though visually a puck from flat do look different than a conical). I often find that flat burrs tend to produce flavor characteristic similar to each other (Super Jolly,Compak K3, Mazzer Mini, Mazzer Major, Mythos), and same for conicals (Rosco Mini, Compak K10, Pharos, Hg-1 ). Just a trend I've observed. Fundamentally (as it should), it is the grind distribution that contributes to these similarity/difference but again it's not something that I can observe by eye.

I am yet to be convinced that a 90-95% aligned grinder will taste that much better than 99% aligned grinder... (I am open to it though, which is the purpose of the OP) So not really sure about the speculation that an ultra-aligned grinder will taste significantly better/different than a 'normal' grinder with acceptable alignment.

I might not be clear previously. What I'm proposing is, when presenting an EY, do include an associated TDS used to reach that EY. Because it doesn't make sense if I get an EY of 25% that tastes good, but I have to pull to a TDS of 7%. TDS would contribute to mouthfeel/body which is part of the tasting experience. This is something which I thought was weird all along the EK43 discussions (especially when that number is readily available on hand).

An example would be "I've extracted 23% from xxx coffee that tastes absolutely amazing, and I manage to stay at TDS 11%. (something in that nature).

nickw wrote:I think that's making an incorrect correlation again in regards to conics vs flats.

Why would that be? From looking at the distribution charts, there don't seem to be a difference between flat and conical.

Microfines might be an area that we have not explored fully (particularly the role it plays on mouthfeel). I'm not sure what's the exact protocol Mahlkonig and the rest are using, but how do they separate those micro particles smaller than, say, 10 microns from the bigger ones? Do they exist?Do they dissociate from the larger particles to give accurate enough reading? There is a possibility that even those particle distribution charts do not tell us the whole story.

nickw wrote:Either way, when using the refractometer (and filtering the espresso before hand) you end up filtering out all the particles in suspension.

It is indeed the fact the filter is filtering out the microfines/fines, which is another reason why the refractometer measurement and EY are not telling the complete picture. Microfines certainly play a significant role on the tasting experience, both mouthfeel and flavor( for instance Turkish coffee).

I share the same view as you regarding David's work. Not all the articles/work should be taken as gospel. But some of them are indeed gems or puzzle pieces that help us to further understand what's going on. And kudos to him for publishing them publicly (and quite candidly).

nickw wrote:Hi Sam, so many things I can respond too. And I have this bad problem with trying to be thorough.

Awesome... Thank you!

Really interesting thread. I think part of the conflict is we're trying to change the definition of the drink. Traditionally, grinders were designed to be easy. Grind dark roasted coffee, place in machine, pull shot. The goal was to minimize required adjustments and maximize consistency, this goal seemingly ended up with the Robur and others like it.

The rules are changing about what an espresso can be and so the grinders and espresso machines are changing as we try to figure out what is possible.

Ira