What happens if you pitch more than one type of yeast?

[rcd]

I know... weird question... the practical implication here is I recently had to pitch a Whitelabs tube after my Wyeast packet failed to ferment after a few days. They were both "London Ale", but technically they were different yeasts.

That got me thinking, what happens if you put two different strains of yeast into the fermenter... a) two similar types of strains (both California Ale, for instance), or b) two totally different types of strains.

I'm guess it'd be weird but I've never read anything about the subject.

 

[david_42]

Some of the commercial yeast packs are actually mixes of several yeasts. Sometimes for flavor, sometimes to improve focculation. I know from personal experience that Cal V and Nottingham focculate into something that looks like white taffy and the ale is crystal clear.

 

[Exo]

If you use two yeast strains in one beer you should finish the fermentation and bottle as usual. Then air-mail them to me and I will properly dispose of them for you. It has taken years, but the disposal system I have is absolutely perfected!