I brewed a batch of oatmeal stout today, with an ingredient kit from LHBS. I got a Wyeast Smack Pak (Irish Ale 1084), and activated it about 4 hours before I anticipated pitching. Well, once again, I overshot my target temperature on the wort. I rapidly got the concentrate down to 70 degrees (in under 20 minutes, this time). But, unfortunately, the water I had in the fridge was a lot colder than I anticipated. I put two gallons in the primary, and added the wort concentrate, and the temp was 53 degrees!
So, I topped off the wort to 5.25 gallons with some pretty warm water, to get the temperature close to acceptable pitching temp. It pushed it up to about 58-59 degrees. I aerated the wort like crazy, all the while hoping the temperature would rise a bit. After about 1/2 hour of doing this, I was at about 60-61 degrees. At this point, I started getting concerned about the batch being exposed to the outside air for too long, and it appeared to me that the Wyeast pack was about to burst, so I decided just to pitch, and hope that once the wort got to about 65 degrees or so, that fermentation would commence.
Am I going to be alright by doing this? I don't think the wort was too cold to shock the yeast, not by a long shot. I just hope that there isn't some adverse affect to pitching at too low of a temp that I'm unaware of.