However, in two lines of dimes vs. two lines quarters that cover the same linear distance, there are more holes with dimes than quarters.

http://en.wikipedia.org/wiki/Sphere_packing

Personally speaking, although I would regard such "hard data" as particle size distributions to be interesting, in the end it would have zero impact on my actual practice of making shots. To me, taste is going to be all and the explanation of it (if something like particle size distributions can explain it, which I'm not really sure of) secondary.

We are all (or almost all) using visual cues as to when to terminate a shot. Do we know that these cues are really valid? Should these cues change over time as the coffee ages or factors such as humidity changes effect the appearance of the extraction? Does blonding in a 3 day old coffee mean the same thing as blonding in a 9 day old coffee? My guess is NO, since I'm unaware of anyone successfully correlating the "eye-cupping appearance" of a shot to its actual quality.

Having great grinders combined with trying to consume most of my coffee during a short time window (averaged among various coffees, say between days 4 and 8 post roast) has greatly simplified this process for me. I think that using the freezer to maximize the amount of coffee that is consumed when the coffee is in its prime would be another factor that can simplify things, and reduces the need to think too much about how to deal with changes in coffee many of which can be avoided altogether if most of the coffee is consumed at its peak.

ken

Ken Fox wrote:Personally speaking, although I would regard such "hard data" as particle size distributions to be interesting, in the end it would have zero impact on my actual practice of making shots. To me, taste is going to be all and the explanation of it (if something like particle size distributions can explain it, which I'm not really sure of) secondary.

"Yeah, but how did it taste?" is a knee-jerk response on many threads, and seldom adds anything of value to a discussion. Taste is important? Wow, what a surprise.

There is obvious value in trying to uncover the fundamental mechanisms of espresso extraction. Random search works, but it's much more efficient to explore the extraction space with the equivalent of a good topo map. This is not about using particle sizing data in your kitchen, but having solid theoretical and experimental support for simple guidelines (like adjusting dose rather than grind as the coffee ages). I'm convinced that a better understanding of espresso extraction will eventually translate into better results in the cup.

The other points you raise (the value of visual cues, freezing coffee, popcorning) are all good ones, and deserve to be explored on their own threads.

Ken Fox wrote: We are all (or almost all) using visual cues as to when to terminate a shot. Do we know that these cues are really valid?
...I'm unaware of anyone successfully correlating the "eye-cupping appearance" of a shot to its actual quality.

Well, as John pointed out, "How did it taste?!?" seems to be the first question that everyone asks, and it's probably the first answer that you get from seeing something in the pull. You see something, you taste it, and if it tastes good, you try to do whatever you did that made it look like that, so that it will taste that way again.
There are rafts of folk here that suggest that our visual cues are anything from invalid to out-and-out rubbish. But, it's how most of us regard the coffee bean itself, the grounds, the pull, the puck, and the product in the cup before we taste it. Naturally, we compare what we see to what we taste, and our little rat brain tells us that this thing that looked like this tasted good, or that thing that looked like that tasted bad.
Am I suggesting that the way that a pull looks will always indicate how good it is? Hardly. I've had too many shots and beans and such that looked off, or even bad, but tasted great. OTOH, I have had so many shots that looked great and tasted great, that looking good is a strong indicator of good taste for me.
When I'm in a new coffee shop, I can usually tell if I'm going to like the shots I get when they are pulled, by what I see. Someday, I accept, this may be an inaccurate metric, but it's been pretty reliable so far...

another_jim wrote:I vaguely recall that you switched to low dose shots after Andy and I did our extraction experiments and wrote them up. Nobody would have tried this without the hard data.

I think your recollection of the timing is correct, although you posit a cause and effect that is not. I was very reluctant to even try lower dosing and I tried it because you said that lower dosing made many more SO coffees work when used for espresso. Any part of that suggestion that had to do with your extraction experiments is more than I remember, although that may have well been what motivated you to make that suggestion.

By the way, a high priced lawyer once told me that if you are on the witness stand, or being deposed, it will never help you to qualify the certainty of your recollections (e.g. I vaguely recall . . . .)

another_jim wrote: People tend to change their SOPs not on someone saying that this tastes better than that, but because there is some sort of rational reason to believe the better results will be consistent. That requires both testing and a physical justification. You tested freezing, and based on the results, and the simple chemistry of cold slowing down chemical reactions, people accepted it. If we had posted the same results in support of storing the beans in ovens, nobody would have been impressed.

I'm not one of those people. I believe that most of what passes for "rationality" in discussions like this is massaged BS, with NO REFERENCE WHATSOEVER to you or the fact that you posted that, above. I personally think that people started freezing coffee before any of my/our studies were written up, although they were ashamed to admit it. The fact that multiple tasters have been unable, in blind tastings, to tell the difference between previously frozen and never frozen coffees, has had a much bigger influence (by reinforcing the readers' own experiences) than any attempt at explaining this phenomenon in a rational way.

ken

Changing your SOP requires some type of exploration beyond the status quo. These changes are inherently guided by a heuristic, be that random--'whatever tickles your fancy' or [pseudo]rational--'ideas that make sense to you.' Collecting dry data (such as how grind changes effect grind distribution on certain grinders) could wind up providing some guidance for a new 'revelation' on methodology, which would quite naturally be fleshed out by testing "in the cup" results, and this guidance could easily mean that we find something new and cool much sooner than we otherwise would with the random heuristic. I fail to see how that is BS. FWIW, your study on freezing was a big part of what motivated me to try it.

The problem is that people take what it is that they want to take, from whatever supposedly "basic research result" (an example, being, however not meant to be more than a simple example) scanning electron microscopy of grind particles, and they read all sorts of meaning into it. What I'm saying is that we tend to be selective, and we (most of us) grab onto whatever "piece" of info from the larger pool, that tends to support what we already believe. Of course, present company is excepted from this discussion

My bias is that I'd rather find what works on a very basic, sensory level, then try to explain it. When we go in the other direction, e.g. we make some sort of molecular finding, and then we try to find some way in which that molecular finding manifests itself in taste, that is where we get into trouble and that is what causes my BS meter to redline.

ken