Jon Webster wrote: I also think it's a little bit of a cheat to just tick off components in a blend, I do try to make sure the variety I check off is at the very least a majority player in a blended wine.
I agree, but on the other hand, this might be a business opportunity for a struggling winemaker. If joining Century Club became popular, and blend components count, plant 2 rows each of Grapello, Grechetto, Plavina, Negrette, Assyrtiko, etc, make them each 3% of your blend, the candidate drinks one bottle, a bottle of Beaucastel*, and a bottle of a cheap red Bdx that uses all 5, and voila! Halfway there. They could sell out just based on offering 33 grapes!
* Peter's example above is the most egregious, as obviously most CdP don't use all the varieties.