Still reading through How to Brew. There are plenty of different yeasts. John Palmer suggests using 2 packets of yeast to ferment with to endure there’s plenty of yeast. I haven’t come across any mention of using 2 different yeasts though. If one yeast gives so and so characteristics, and the other gives such and such, do you end up with such and so, or does one yeast outdo the other, or do problems ensue?
AFAIK, in beer, either (1) or (2) but not (3). There are “killer-positive” yeasts that will actively kill others, but I don’t believe any beer strains are among them.
It’s hard to know what will happen without trying it. Different strains reproduce at different rates, and it’s likely that one will out-compete the other, but you may still get some combination of their characteristics.
One yeast will typically dominate the other, but not to bad effects. Give it a shot!
I can see it now, Yeast Wars: The Empire Strikes Bock! Bock lager yeast fermented with yeast previously used for an Imperial Stout.
Yes there are kill strains out there, mostly Red Wine and they only effect Saccromyces, Brettanomyces won’t get “killed”. That being said, doing a layered fermentation is in my plans, using a wine yeast to eat up all the simple sugars and produce their flavors, then add in a beer yeast to handle the maltose.
the best source of info on this topic that i’ve ever seen is the 11/22/08 episode of the session on the brewing network with shea comfort. i’ve listened to that episode seriously about 8 times and have learned something new each time. you can tell that the guy is just brimmed with more info. dont miss his discussion of oak on the same episode. you couldnt pay to get this kind of info.