Originally Posted by Sawdustguy
The only caveat is that some commercial breweries add a second yeast to promote the beer's effervescing in the bottle. The question is whether you are culturing the fermentation yeast or the effervescing yeast?
Have you heard this about lagers in particular, or just breweries in general? I had read about certain breweries (I think Chimay was the example given) doing this as a response to people culturing their yeasts from the bottle. There is a list here
that has information on what yeast is in the bottle for certain breweries (it contradicts what I'd read about Chimay).
Also, I've heard in podcasts by The Brewing Network that beers like hefeweizen are sometimes dosed with lager yeast in the bottle. The reason given was that it doesn't flocculate well and stays "powdery" to give the cloudy appearance appropriate to the style.
I'm hoping that these smaller regional breweries are keeping it simple (traditional?) and only using one strain of yeast for everything.
Honestly, whether it's really the primary yeast of the brewery it came from is a pretty low priority to me. I'm mostly doing this so I can say, "hey look, this beer was made with Swiss yeast from when I went to Switzerland".