I was thinking lately about the debate over the blind triangle test being the best if not only way to determine difference. Some say that every detail must be the same, but for the one issue being tested. Cool, I get that idea.
How would we apply that to comparing a fresh pitch to a subsequent generation repitch? For a 1st gen vs 2nd gen you would be compairing beers brewed several weeks apart with different wort, or you would have to split a batch of wort and use a different 1st gen pitch to compare to a 2nd gen from a different batch of yeast.
Wouldn't we have to stipulate that using a different lot of 1st gen yeast would be acceptable, or stipulate that its OK to store the 1st gen beer until the 2nd gen beer was ready? There's a lot of techy brewers that would invalidate either idea.
Where I'm going with this is that there are times when personal opinion based on memory comparison should be acceptible, and/or... we need to recognize that we don't have prove everything scientifically.