Originally Posted by Hoppyending
Wow. Not gonna restart this argument. There is plus and minuses to both.
Dude, your argument makes zero sense. You're talking about there being toxins in the water that can't be boiled out that will harm the yeast.
What water are you making your wort with? Wouldn't those same toxins survive the boil, and then harm the yeast when you dump the pack straight in.
The bottom line is, rehydrate your yeast. Numerous people have done experiments. You lose a minimum of 50% of the yeast if you sprinkle the dry yeast directly on the wort. You still lose quite a bit of yeast if you rehydrate in water that is too cool (aka room temp).
It's not hard to heat some clean water in the microwave to 90-100*, and stir in the yeast. Take the 2 minutes to do it. And don't listen to this guy about toxins.
The advice IS
bad. You can do whatever you like as personal choice, but telling a new brewer to do something that empirical and scientific data suggest against is bad advice.