Expert: Ed Westemeier - 1/17/2010

Question
I was in the middle of cleaning up brewing a batch today and was in a hurry. I was recycling yeast from one batch to the new one and accidentally pitched the yeast into the wort when it was probably still around 125 degrees. The yeast quickly started activating the sugars in the wort and bubbles of co2 seemed to come out quiker than other batches I have brewed up. Will there be any side afects to pitching the yeast early, will it cause bacteria, or other things to grow in the beer?will it alter the taste, body or anything else?  

Answer
You don't have to worry about nasty critters growing in the beer, so that's the good news.
However, there are some possible flavor effects you should be on the lookout for.

The high temperature was still low enough that you didn't kill the yeast, so that's a good thing, but when yeast works at elevated temperatures it makes different byproducts during fermentation.

You might experience a higher level than normal of esters, with the possibility of fusel alcohols. Nothing dangerous, but they can cause off-flavors if they are at a level higher than your taste threshold.

I can't give you any definite answer, because it really depends on whether the potential off-flavors (and I say potential because you might get lucky and avoid them) are above your threshold.

Just relax and make sure your fermentation is completely finished. If you don't like the flavor of the finished beer, then you've paid the price for your problem yesterday. On the other hand, there's a chance you got lucky and the beer will be fine.

Here's wishing you good luck.
Ed