Emc2 Also, what is the minimum difference in EY that can be detected by taste? Ultimately that is what matters.
Not really, again, the devices are marketed on their effect on EY. Cups at the same EY (within reasonable expectation) will still differ in taste, +/-0.3%EY has been mooted as the detectable level, but I don’t personally think it is that clear cut. A coffee with 10 brews at the same parameters might have a stdev of 0.4EY and this be considered good/acceptable, but we’re brewing tiny amounts, in short times and, yes as you say there will always be some variability that we cannot control. Context and reasonable expectation is important in making sense of this.
EY is an objective measure of brew efficiency and useful for gauging objective consistency. It has been found to have a correlation to regions of interest where people have a preference for taste too, but it is not a direct indicator of taste/quality (as stated for the last 70yrs), hence why I think it important to also have taste scores - EY without taste is too vague to be meaningful, taste scores without an objective value makes troubleshooting & sharing more difficult. (You can’t fix a coffee you will never like by knowing EY, you might be missing out on a better result with one you do if you are consistently off in EY).
If you are going to carry out tests yourself for your channel, it would be informative if you did some EY measurements yourself (follow VST protocols whichever refractometer you buy).
My apologies, I didn’t notice at first look that Lance only did 8 measurements per condition (he does state this in the video), I agree a larger sample size would have been more robust (He stated that he pulled 100 shots…I wrongly assumed that would be enough to get at least 10 per condition).
Yes, double blind testing would be ideal, with sensory testing amongst a random sample who are unaware of what the test is…but now you are talking thousands (or tens of thousands) of pounds, teams of people & finding people in the street who drink espresso…good luck with that 😀
Look around your coffee gear, which device/accessory that you have, or even that you know of, has been tested to the degree that you suggest? It’s the lay of the land that we are reliant on sole agents & garden shed protocols to ‘test’ this stuff. ☺️
