Originally Posted by COLObrewer
Without seeing or reading the entire podcast its hard to say, maybe he was talking about mutation of the yeast? If you make a starter from yeast that has been mutated, you will get mutated yeast.
Did he state that the bittering compounds prevent the yeast from multiplying or inhibit them in some way?
Never heard of yeast mutation, that's a new one one me. What conditions would bring on a mutation of yeast. He didn't mention mutation specifically just that the health
of the yeast would be reduced but perhaps this could include mutation. I just don't know enough about the subject if i'm honest.
Originally Posted by ColoHox
High alcohol and high IBUs have a preservative effect, hence IPAs shipped around the world in the old days. Yeast coming from those conditions will not be at their healthiest to start a new batch of beer.
Although if you can get a starter to take off then the yeast is probably fine.
I was thinking along the same lines. Yes the yeast would not be suitable for a direct pitch but if a starter takes off within a reasonable amount of time then surely new healthy cells are reproducing at an acceptable rate. Definitely don't want to compromise the quality of the final product though, it takes enough effort to make a batch without ending up with some thing that is nearly as good as it could be.