dry yeast hydration

does anyone do anything besides rehydrate the yeast with pitching-temp sterilized water?

I open the pack and dump into the fermentor... I guess that's different... I've never started one.. and never had problems.. FWIW... 12 Batches thus far.

I normally do the same, have for years, but thought I'd try actually rehydrating the little buddies first to see if it had a positive impact.

yeah, I follow Palmers book. He says to rehydrate it and add a table spoon of wort too. I just draw off a tablespoon from the boil (after 15 mins), let it cool and add it to the rehydrating yeasties

I've always just sprinkled it directly on the wort and let it re-hydrate there. After about 20-30 min, I shake it up really good and let it go. Have always had really good results this way.

I usually rehydrate about 20 - 30 minutes before pitching. However, I have pitched directly onto the wort with good success as well.
One thing I can add, my last 10 gal batch was split into 2 primaries. I pitched 1 pack of Notty into each and shook after waiting 10 minutes or so. Some yeast was deposited on the sides of one of the carboy..... a bit more than the other. Granted, not much compared to what was in each pack, but some none the less.
The one with "less" deposited on the sides had a big blowoff. The other didn't need anything more than a regular airlock and blew off nothing. That being said, it would seem that rehydrating would go a long way to getting all of the yeast into the wort instead of just "most".

To get the benefit of higher pitching rates associated with dry yeast, it should be rehydrated. The dehydrating process is pretty rough on the yeast. The ones that are left alive are dried out and weak. Dumping them into sugar rich wort can cause osmotic shock. That is the sugar in wort will draw out any remaining moisture in the cells. This leaves a weak cell wall, making it harder for yeast to bud (reproduce).

Per Jamil, the yeast companies tell wineries, who use a lot of dry yeast and even pro brewers to rehydrate. Why not us? Dry yeast is roughly 20 billion cells/gram, (mrmalty.com). You get about half that viability by sprinkling dry yeast on the wort.

Also, if it comes up, making a starter with dry yeast is not necessary. Starters are useful for liquid yeast which only contain 15-18 billion cells (mrmalty.com). The starter gets the cell count up the the ~180 billion cells needed for a middle of the road ale.

Edcculus, very nicely and accurately said!

Nurmey, excellent compliment.... and nicely worded.

Rehydration temperature should be between 85-95 degrees F.

There's lots of good info on the Danstar website.

You get about half that viability by sprinkling dry yeast on the wort.

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Link? Not that I don't believe you, I've just never read anything that specifically breaks down how much viability you lose by pitching dry.

FWIW, when I said I pitch w/o re-hydrating, that's only for beers < 1.060ish. Anything bigger and I do re-hydrate.

Sorry, I don't have a direct quote. I could dig something up, but it would have to be a Jamil Show or Brew Strong podcast. I know for a fact that Jamil talks about it a good bit on his shows. I believe it is legit since he has done a lot of research on cell growth for the pitching rate calculator.

It may be that you don't loose half the viable yeast, but you do loose some. If someone can prove me wrong, please do. I'd hate to spread misinformation. Whether its scientifically proven or not, I believe it is a "best practice" to rehydrate.

I've pitched it both ways, dry and re-hydrated with about the same results. Always a good drinkable beer. However, I only brew ales and I was always pretty loose with my pitching temps. Luck - Dwain

It may be that you don't loose half the viable yeast, but you do loose some

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Yeah I always assumed I lost at least some...I just didn't worry about it since most of my beers were 1.055 or less and one pack should easily be enough. I could be wrong though, I'd just like to see some numbers. I've always been the skeptical type.

And given how busy I've been lately, it would almost be easier to just pitch two packs and not worry about re-hydration at all. I mean it is all of what...another $2? The risk of infection/killing off yeast w/ the wrong temperature is really barely worth the extra few dollars IMO.