I think dogs are good judges flavor. Those that get two sample people food that is.
My dog will only eat popcorn with real butter on it. No microwave popcorn with the fake stuff. No margarine. And the popcorn he eats has to have enough butter on it, he will sniff it first and it if is not satisfactory he will turn his head away.
Sometimes he will take the “bad” popcorn kernels out of respect, but then I find a pile of them in his dog cushion.
Smart guy!