Please explain different yeast in secondary

[neldred]

I've read that a few breweries (Duvel being one off the top of my head) that use a completely different yeast strand in the secondary. And it's claimed that it's for flavor, not just for the sake of bottle conditioning (come time, after complete clearing in the secondary). Is anyone here experienced at this, if so could you please explain the logic behind it and the methods for choosing the secondary yeast. Thanks.

 

[nebben]

Ok, so I'm going out on a limb here with this, but I would suspect that during the "secondary" they are exposing the fermenting wort to containers that contain desired bacteria and/or wild type yeasts.

 

[neldred]

bumpers