Earlier quoted context omitted.
You don't have to blind a study when the effect size is big enough (the classic example is the ridiculousness of a double-blind test of the use of parachutes). See my other comment for how easily egg flavor can be altered.
He's right to be distrustful. People are terrible at taste tests. If you ask people how something tastes, they will tend to tell you what they think they're expected to taste rather than what they actually do. There's plenty of scientific evidence for this based on wine studies[1], but on a personal level, the tongue map myth[2] is the one that gets me. It was taught in science class as true, and we did (non-blind) e…
True, but after being served backyard vs. store eggs without being told which is which, or which feed type was in use, or that anything had changed at all, and still noticing a difference, I am confident that it is possible for the flavor of eggs to vary.