The reason I recommended buying coffee within days of its roast is that you'll probably drink that same batch over the next week or more. Things start going dow

The reason I recommended buying coffee within days of its roast is that you'll probably drink that same batch over the next week or more. Things start going downhill after around a couple of weeks off roast. So, if your coffee is 1+ week old when you buy it, it's probably going to be missing something for at least some of the days you drink it. I drink mostly decaf these days, and it stales even faster than regular. The difference is so stark, that to get a consistent espresso extraction I have to adjust the grind setting finer as the coffee ages. If a 10 on the Niche Zero is where I dial in coffee 4 days off roast, I'll typically need to dial down to an 8 by the end of two weeks. Still, I don't have any trouble believing the results of your experiment, or the YT video's experiment. Two weeks is still pretty fresh. But if you repeat your experiment with 4-day coffee vs. 4-week coffee, maybe your tasters will be able to detect a difference. (Also, depending on how you prepare it, 1-day coffee might be "too fresh"; it's still outgassing a lot. I'd suggest you try 4-day coffee as your control.) If you try decaf, I'd expect the difference to be more detectable. Anyway, thanks for the empirical evidence.