insubordinateK
Well-Known Member
Here is a nice study which suggests some strains resist genetic variation for hundreds of generations when there is little selective pressure. It also suggests the number of times that a commercial brewery will re-pitch the same yeast before re-propagation will depend on the susceptibility to genetic drift.
http://www.scientificsocieties.org/jib/papers/2007/G-2007-0420-478.pdf
http://www.scientificsocieties.org/jib/papers/2007/G-2007-0420-478.pdf