another_jim wrote:To me this seems almost logically impossible.

ALMOST?


To change the "taste experience" (combination of aroma, flavor, body, consistency, etc.) one must change the dose/grind combination. It is also possible to change the tamp but I believe that tamp only changes the taste experience if the flow characteristic is altered.

So if you are already following a low-dose soft tamp routine for a normale shot and you then do a handstand tamp to make a ristretto shot from the same dose and grind then the taste experience will be different. If you have the same dose and grind creating the same flow...then it will taste the same (within my personal limited ability to distinguish tastes).

CoffeeOwl wrote:And also, a techninque of puck preparation like WDT affects the taste, and from my experience - it does so because it changes the layout of particles of different sizes in the puck.

There is zero evidence to support this little piece of folk wisdom. Neither you nor anyone else has ever tested WDT-related particle size changes in the puck. How would you even design an experiment to examine this?

If WDT really does change the taste of your pours, then I can supply a far more likely explanation: without WDT, your puck prep is flawed enough to cause channeling or some other form of uneven distribution. This leads to uneven extractions, which cause detectable taste changes.

JonR10 wrote:I don't need to use WDT with a Robur grinder but I still like to because it is so clean and SO consistent.

+1. I don't believe for an instant that I could blind taste the difference between puck preps using WDT, nutation, whatever, as long as they produced an even distribution of grinds in the basket prior to tamping. I still use WDT because it's the most convenient way for me to achieve that even distribtuion.

WDT was with me all the time straight because of the same reason, its being the most convenient way of redistributing grinds in the basket (I don't use and never used any yogurt cup or similar item for that, though). Yet, after I acquired a couple of hand grinders, I discovered WDT spoils the extraction. It was still the most convenient way of making the even bed of grinds, despite that there is the drawer from which you dump the grinds to the basket. Why was that?? the flow was nice at beginning but then collapsed earlier and went blonding earlier. Without WDT it is running nice even way even longer.
The logical explanation is fines migration. Of course particles sizes distribution will always be wider with a hand grinder then with a Mazzer.

As for the logical explanation of taste changes, Jim, you did yourself detect different taste from different grinders, while they were adjusted for the same flow, right?

I can agree that it is in fact via alteration of flow that the difference occures, but this difference in flow is small enough that it gives the same volume in the same time within the same stop point. So in a way it is hard to say it is flow difference because it is not visible nor measurable (with variables like volume or time, nor evident by sight).

For the tamp... yes on Vivaldi you have to change grind setting for light tamp from a hand-stand tamp to get the same flow. BTW, actually the flow remains the same but this alteres the moment when the shot starts blonding - it does earlier with the light tamp. Taste is milder, as general.
On Caravel, when you tamp hard you have to loosen the grind, but then this is another spectrum of variables - because with this machine one should actually match the dose to the basket. But this is another topic, also discussed now somewhere in the forums... do baskets have a preferred dose. After having experience with all three Caravel baskets I tend to think that yes they do. And so a normale-tasting shot can be made in appropriate volume (matching brew ratio) from different doses unless apropriate-sized basket is provided: for example on Caravel there is this 12g-holding basket and bigger 14g-holding one.
So when tamped hard, the shots have some less tenderless and more dry-like bitters (but mind you, these are nuances, not major characteristics of the shots in any way).

JonR10 wrote:... a handstand tamp to make a ristretto shot from the same dose and grind ...

Is this possible?

I'd truly like to see a two group test using a full doser of freshly ground coffee, weighed doses below screen contact and reasonably calibrated tamps show a consistent difference.

IMO, the only time a heavy tamp has any effect is when the puck will touch the screen on lock in. The extra ½mm clearance maybe essential.

at least on e61s

CoffeeOwl wrote:...after I acquired a couple of hand grinders, I discovered WDT spoils the extraction. ...
The logical explanation is fines migration.

The most logical explanation is most certainly not fines migration. As I noted recently in another thread, fines migration is postulated to occur in a near-boiling liquid medium under 9 bars of pressure, not with dry coffee grinds at room temperature under normal atmospheric pressure. Again, poor puck prep (and channeling as a consequence) is a far more likely explanation.

You have already modified the WDT by not using the funnel. What do you use to stir the grinds? The use of fat stirring implements (chopsticks or even toothpicks) could create channels in the puck. A dissecting needle is still my tool of choice.

another_jim wrote:If shots dosed and ground the same don't flow the same, the prep technique is inconsistent, not creative.
...
The more time we waste discussing the spurious discoveries of sloppy baristas, the less time we have to talk about actual coffee.

Like Jim, I am suspicious of overly fragile methodologies. This encompasses all rituals (including WDT) for grooming and tamping that reputedly lead to espresso nirvana. Given the correct grind and dose, any technique that produces reasonably even distributions should give you good results. There are many things that could "spoil the extraction" but I seriously doubt that a WDT stir is one of them.

RapidCoffee wrote:Like Jim, I am suspicious of overly fragile methodologies.

This terminology expresses exactly what I've been thinking about espresso prep lately. It reminds me of one of my other hobbies, radio contesting, where people spend thousands or even tens of thousands to get 1dB more signal gain. There's a bit of voodoo superstition in this, and possibly some placibo effect as operators are convinced that it actually produces significantly better results.

At times I've caught myself getting OCD about tiny things like a half-BAR of pressure, a half-degree of temperature, a few seconds of flow time, a tenth-gram of dose, sweeping every last grain of coffee out of the grinder/doser, filling evey gap in the surface of the puck, etc., etc., etc.

But what I found really affects taste are these things (adding to/expanding on Jim's list):

1. The coffee -- of course.
2. Freshness, especially if, like me, you use a self-defrosting freezer.
3. Dose -- this has major impact on the flavor profile
4. Grind -- ditto
5. Temperature -- a more subtle effect

The combination of coffee, dose and grind define the flow rate, so I didn't list it separately. Basically, I think of the flow rate as producing a certain extraction ratio (extraction weight / coffee weight) within an "espresso-reasonable" amount of time (20-30 seconds.) This is roughly the same thing as whether the coffee tastes best to me when pulled ristretto, normale, "standard" or lungo.

I used to be pretty OCD about shot time, always trying to hit either 25 seconds or whatever time was recommended by the roaster or reviewer. But more recently I've allowed some leeway in this, using the grams of weight in the cup and the blonding point as the indicators of shot completion and being more relaxed about time. For example, if I'm pulling a ristretto, and the blonding point and approximately 1:1 extraction ratio occur at 32 seconds, I don't obsess that the time ran a little long -- provided that the shot tastes good. If it tastes underextracted, then I'll consider adjusting the flow rate to be a little faster, either by lowering the dose (easier and probably the first thing I'll try) or loosening the grind.

One thing that convinced me about the generality of shot time recommendations is that different machines, doses and grinds produce different dwell times (time to appearance of first drops of espresso). I believe Jim recommended adding half the dwell time to the remainder of the shot time to get the total time. I kept finding that shots tasted better if the pull time was towards the higher end of the range, and when I deducted half the dwell time it fell much closer to the so-called ideal time of 25ish seconds. But even if it didn't fall within the 20-30 second window, I still think taste has to be the guide and shot time is only a general target. It's true that the longer water is in contact with the coffee, the more likely it is that undesirable flavor components will be extracted, and it's likely if your shots are running 40-50 seconds they're probably not going to taste very good. But I'm not convinced that a few extra seconds have all that much impact, and certainly not as much as coffee/dose/grind. I think the effect shot time has on the result is roughly similar to the effect of temperature, which is fairly subtle within a narrow range (with the caveat that some of our tasters seem to be much more sensitive about these variations that I am.) Sure, if the shot runs really long (say 40-50 seconds), then the water has been in contact with the coffee a long time and will probably pull some undesirable flavors out of it.

As far as prep goes, with my gear I've found the only really important things are making sure 1) the distribution isn't drastically uneven, 2) the edges of the puck are sealed (i.e., light NEWS tamp and/or nutating tamp), 3) the puck isn't noticably canted. This ensures that I don't get a blond gusher, spritzes, channeling, etc. Once those defects are eliminated, it's all about the extraction ratio and blonding point (both of which can be thought of as being defined by the flow rate.)

In a sense, Jim's statement is a semi-tautology. If you eliminate flow defects, then the taste will be defined by the flow rate, which in turn is defined by the coffee/dose/grind. The taste will be optimum at some flow rate, which can be measured by volume or extraction ratio and the blonding point (assuming a "reasonable" flow time) You can tweak the temperature or pressure and get small changes in taste, but assuming the flow quality and rate stay the same, altering the tamp and distribution ritual won't change the taste.

I have written myself about the way I do the WDT and personally recommended apropriate devices couple of times and commented on unapropirate ones. The responses here are making me laugh really.
Do you think that I can comment on extraction eveness, flow, etc. and not notice I get extraction problems like channeling or other?

To the fines migration or whatever you call it - I am talking of what is apparently visible and noticable for everybody, for example if they knock basket full of grinds a couple of times against the counter - the grinds change the way they are laying in the basket and the finer ones get lower while the bigger ones will be higher. This happens while stirring the grinds too.

CoffeeOwl wrote:To the fines migration or whatever you call it - I am talking of what is apparently visible and noticable for everybody, for example if they knock basket full of grinds a couple of times against the counter - the grinds change the way they are laying in the basket and the finer ones get lower while the bigger ones will be higher. This happens while stirring the grinds too.

"apparently visible and noticable for everybody" - Well, certainly not to me. I've never observed a puck prep redistribution of particle sizes, and IMO this is a preposterous claim. You really believe your eyes are good enough to quantify the size redistribution of dark clumpy particles, with diameters ranging from 10 microns to slightly under a millimeter in size, inside a filter basket?

I do not intend to pursue this nonsensical debate any farther. Have fun with your particle size eyeballing.

cafeIKE wrote:Is this possible?

It is simple enough to run a test for yourself and see.

cafeIKE wrote:IMO, the only time a heavy tamp has any effect is when the puck will touch the screen on lock in. The extra ½mm clearance maybe essential.

I believe you are wrong, but this is purely based on my own experience.
It has nothing to do with touching the group screen (please note what I said earlier about LOW DOSE)

JonR10 wrote:So if you are already following a low-dose soft tamp routine for a normale shot and you then do a handstand tamp to make a ristretto shot from the same dose and grind....

Perhaps with singles tamp doesn't matter, but for 16-18g in a double basket ground for a normale flow from a soft (~10-20 pound) tamp then a firm tamp (~40-50 pounds) most certainly does change the flow.

RapidCoffee wrote:"apparently visible and noticable for everybody" - Well, certainly not to me. I've never observed a puck prep redistribution of particle sizes, and IMO this is a preposterous claim. You really believe your eyes are good enough to quantify the size redistribution of dark clumpy particles, with diameters ranging from 10 microns to slightly under a millimeter in size, inside a filter basket?

I do not intend to pursue this nonsensical debate any farther. Have fun with your particle size eyeballing.

Yes, for everybody that has a microscope in their eyes. Good you don't intend to take this longer. If you claim that all grinds that you see in the basket with your eyes differ in size in the range of microns, good to you. Technocratic dreams.