AssafL wrote:Do you really believe there is a POS end to the espresso machine curve? I ask because I find it hard to believe any of the leaders on this site (like Jim, Dan, Nicholas and many many others) will fail to get a decent if not a good cup from any combination of machine/grinder. They may have to realign the grinder, surf the temp, find a different roast, WDT, and then WDT again, replace the gasket, use the lever as a pressure profiler... but eventually show that even the worst machine can (usually) be forced to deliver.
You have completely misunderstood my statement. I just meant its not that easy to evaluate and tease apart beyond noise if performances are close. I am not trying to question anyone's intention or competence, leader or not. As I said, I read reviews to help my purchase decisions and I like reading reviews. And, I appreciate all the effort reviewers put into evaluating the products, sometimes selflessly. I am merely providing a cautious note. Like, their is difference between reaching conclusion that ECM technika lacks water indicator and its a major inconvenience vs Model A E61 machine extracts certain flavors better than Model B E61. Not that later conclusion cannot be made. Its just that its much harder and nuanced than most people think and appreciate.
Reproducibility of results assumes an objective tester. Once subjectivity sets in (and I think that is the crux of Jim's post - if I read it correctly) the question is "will I prefer machine X" and not "is machine X better".
There is nothing objective about coffee. That's why a wide range of methods and models exist and are thriving
However, it is possible to design a objective experiment. Just as random example.
Goal: Which machines among 5 selected produces an espresso that is liked by Assaf
Ask 1 barista to use beans Assaf likes, dial the best espresso, and present them blinded to Assaf: Total 5 shots
The nuts and paddles don't matter as this is Input-->Black Box-->Output kind of design
Now, will you be more confident with this design or
New Experimental design:
Ask 5 baristas that are expert for each machine to produce 3 shots on each machine and present them in random order to Assaf: 5X3X5=75 shots (Good luck drinking that much coffee
Which one is likely to give a better result? Where do you draw a line on minimum samples necessary to make a call? All answers are in maths and statistics, if people do not cheat them to suit their design constrains.
I have simplified the goal. Imagine if goal was to find: which machine makes the espresso liked by most people in certain country?
Forget four M's, four S's are more important :-)- see, sniff, sip and savor....