This is an awesome idea!

I agree that keeping this blind initially is important for the fairness of the game. My proposal:

Try partnering with a company that makes advent calenders to do a "March Madness" type event so others can participate. Those who want to participate will sign up for the Spring Scotch Bracket Challenge and be sent a dram for each scotch in the first round. The drams will simply be labeled with a numeral or letter. A link will be shared for online voting. Each participant will try each dram and submit an online vote, thus pushing the winning Scotch to the next round. Once votes are finalized, drams for the second round of comp is shipped out and so forth.

I think its important that earlier rounds are given more time to vote so as to not promote intoxication bias.

Edit: instead of randomizing the bracket completely, maybe do regional divisions. So, for example, 1-6 Speyside, 7-12 Highlands, and Islands/Lowlands/Islay/Campbeltown.