Re-Yeasting the primary?

Just a question that popped into my head while I was making my brew this afternoon. Hypothetically, if a yeast failed to activate after something like 72 hours and fermentation never began (say, the yeast was pitched in too hot of a wort). Is it possible to add more yeast to begin the process? My guess would be yes, but would the dead yeast introduce any off flavors? If it has alcohol in it, chances are I would still drink it.

Cheers!

Mori ...

If for some reason your yeast did not start fermentation (which is rare unless something dumb is done) you can pitch more yeast. From what I have heard, if you have dead yeast, the active yeast will feed on them similar to adding a nutrient.