I don't know how these wine comparisons are done, but it's tricky to set up comparisons.
A famous version of this was the "Pepsi challenge". It turns out that people preferred the taste of pepsi in the test conditions, but coke in other, longer testing conditions. So part of it is biochemical (e.g. the taste you experience on the first bite/sip of something is not the same as the 20th) but some is also mental. Your experience of the taste of something can change with the environment you sample it in.
A famous version of this was the "Pepsi challenge". It turns out that people preferred the taste of pepsi in the test conditions, but coke in other, longer testing conditions. So part of it is biochemical (e.g. the taste you experience on the first bite/sip of something is not the same as the 20th) but some is also mental. Your experience of the taste of something can change with the environment you sample it in.