Originally Posted by JonK331
Yes. Also keep in mind that not rehydrating can kill up to 50% of the yeast (yes I know this is a controversial issue but skipping the rehydrating step increases risk unnecessarily).
This is handy to know.
When I was starting out brewing, lo, these many months ago, I used mostly packaged kits from my LHBS. All those that I can remember said to sprinkle the dry yeast over the surface of the cooled wort in the fermenter. I've just done it this way and never given a second thought, as I've had decent results.
I've known about rehydrating, but never saw the point, since the cell counts in dry packages are often twice as high as in the smack-packs.
In the course of improving my practice of the craft, I've been reading recently about yeast handling and using proper pitching rates, etc., but I can't recall seeing a reference to the potential risks of not rehydrating.
Since rehydrating is minimal hassle, and the cell count risk is so extreme, I think I'll be rehydrating from now on, any time I'm using dry. (I've moved on to washed yeast cakes for most of my brewing, but this is a handy nugget to keep in mind when I do use dry.)