[
previously]
With
mew0422's help on the study design, she, her mother, and I all did a three-way double-blind taste test among Coke, Passover Coke, and Coke Zero.
Protocol
To double-blind ourselves, one of us affixed labels, A, B, and C, to the bottom of three identical glasses. Another filled each glass, noting which was labeled as which, and the third of us shuffled the glasses, noting that permutation. That left us with three glasses looking identical so none of us knew which was which.
We tasted and noted on a piece of paper which we thought was which, and which we liked most.
Results
All three of us were able to discern which was which, generally liking the Passover Coke over regular Coke over Coke Zero.
mew0422 liked regular Coke for being less sweet than Passover Coke (HFCS is less sweet by mass than sucrose). Her mom made a disgusted face upon tasting Coke Zero.
Bottom line: You too will probably be able to tell the difference so the difference is not that subtle.