i have bben to only one small brewery and i asked them this very question. he said that they have some yeasts that they will harvest but no more than 2-3 times. after that there is risk of mutation. he said that they did have one or two yeasts which were given to them in germany which they pay a lab to cultivate.
it's not the blood you've spilled that gets you what you want, its the blood you share. friends, family, community: these are the most valuable things a man can have.
on tap- lemongrass kolsch
on tap- stout
on tap- small mead