[Three]

You don't need to pitch extra S-05 because you didn't rehydrate.  I go by my OG - if I get ~ 1.065 or higher I"ll  use maybe an extra 1/2 packet, because of the gravity not because of sprinkling it dry.

Awesome!  Now this answer takes me here......

What information is available that says viability is less/more/same when dry yeast-ing?  The info I have run across indicates that there is loss of as much as half the viable cells doing this. I think I read this in the "Yeast" book.  There also seems to be a difference in yeast cell count from the manufacturers and what is out there in the pitch rate calculators.

[HoosierBrew]

You don't need to pitch extra S-05 because you didn't rehydrate.  I go by my OG - if I get ~ 1.065 or higher I"ll  use maybe an extra 1/2 packet, because of the gravity not because of sprinkling it dry.

Awesome!  Now this answer takes me here......

What information is available that says viability is less/more/same when dry yeast-ing?  The info I have run across indicates that there is loss of as much as half the viable cells doing this. I think I read this in the "Yeast" book.  There also seems to be a difference in yeast cell count from the manufacturers and what is out there in the pitch rate calculators.

Use good sanitation and there's nothing wrong with rehydrating if you want.  I just haven't found an advantage to doing so - no loss of attenuation, no stuck fermentations ever by sprinkling on top. It's a highly attenuative, voracious eater, dry or rehydrated. One less thing to sanitize, and therefore, one less sanitation risk. I think the warnings are overblown, as someone who's brewed for a long time.

[majorvices]

People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?
.

Why do Wyeast and White Labs tell you it's unnecessary to make a yeast starter? regardless, base your conclusions on your own empirical evidence. That's what I've done. I do adjust my pitch rate depending on the gravity and I also have adjusted my pitch rate depending on the lag time. 

[Three]

You don't need to pitch extra S-05 because you didn't rehydrate.  I go by my OG - if I get ~ 1.065 or higher I"ll  use maybe an extra 1/2 packet, because of the gravity not because of sprinkling it dry.

Awesome!  Now this answer takes me here......

What information is available that says viability is less/more/same when dry yeast-ing?  The info I have run across indicates that there is loss of as much as half the viable cells doing this. I think I read this in the "Yeast" book.  There also seems to be a difference in yeast cell count from the manufacturers and what is out there in the pitch rate calculators.

Use good sanitation and there's nothing wrong with rehydrating if you want.  I just haven't found an advantage to doing so - no loss of attenuation, no stuck fermentations ever by sprinkling on top. It's a highly attenuative, voracious eater, dry or rehydrated. One less thing to sanitize, and therefore, one less sanitation risk. I think the warnings are overblown, as someone who's brewed for a long time.

That's all good HoosierBrew!  I wasn't trying to aggravate!  Advice from seasoned brewers is very valuable.  I don't mind going through the sanitation process.  Using it dry is way easier though!  I was just looking for the "definitive" answer on pitch rate.  I think that is always what is behind the "use it dry or re-hydrate question" (that shows up often).  With everything in brewing being pretty scientific the specs around dry yeast are pretty loose......

[morticaixavier]

You don't need to pitch extra S-05 because you didn't rehydrate.  I go by my OG - if I get ~ 1.065 or higher I"ll  use maybe an extra 1/2 packet, because of the gravity not because of sprinkling it dry.

Awesome!  Now this answer takes me here......

What information is available that says viability is less/more/same when dry yeast-ing?  The info I have run across indicates that there is loss of as much as half the viable cells doing this. I think I read this in the "Yeast" book.  There also seems to be a difference in yeast cell count from the manufacturers and what is out there in the pitch rate calculators.

Use good sanitation and there's nothing wrong with rehydrating if you want.  I just haven't found an advantage to doing so - no loss of attenuation, no stuck fermentations ever by sprinkling on top. It's a highly attenuative, voracious eater, dry or rehydrated. One less thing to sanitize, and therefore, one less sanitation risk. I think the warnings are overblown, as someone who's brewed for a long time.

That's all good HoosierBrew!  I wasn't trying to aggravate!  Advice from seasoned brewers is very valuable.  I don't mind going through the sanitation process.  Using it dry is way easier though!  I was just looking for the "definitive" answer on pitch rate.  I think that is always what is behind the "use it dry or re-hydrate question" (that shows up often).  With everything in brewing being pretty scientific the specs around dry yeast are pretty loose......

Did you read the link to Sean Terrill's experiments?

For anyone who hasn't seen it yet, this is interesting:

http://seanterrill.com/2011/04/01/dry-yeast-viability/

some good info on exactly the effect of water v wort and dry yeast. if you are going after accurate cell count estimates this is the info you need (well actually for accuracy you need the cytometer etc.)

[denny]

My trick question is this.  Are the folks that are just sprinkling the yeast in adjusting their pitching rates?

Nope, there's no need to.  I get great performance from a single rehydrated pack on beers in excess of 1.075.  Statistics are great, but it's performance that counts.

[ynotbrusum]

There is absolutely no reason to rehydrate, other than the fact that the rehydration process (in water) allows the dry yeast to re-build cell walls and to absorb the nutrient built into the drying process prior to the metabolic stress of the wort sugars being introduced intracellularly.  The viability is nearly doubled by rehydrating with water.  But, the number of cells contained in the typical sachet is well over the number needed to properly pitch almost all beers that I make, other than the occasional big beer.  Reusing dry yeast is somewhat trickier, I tend to pitch almost a third of a yeast cake for ales and almost half a yeast cake for lagers (harvesting the yeast cake at about up to a month from original pitch date).  My results have been great and as said by all above, ultimately, there is no need to do any of the extra effort; but in the end, I like knowing before I pitch that I have a viable yeast being pitched, even though that is rarely an issue with dry yeast.

[morticaixavier]

[...] Reusing dry yeast is somewhat trickier, I tend to pitch almost a third of a yeast cake for ales and almost half a yeast cake for lagers (harvesting the yeast cake at about up to a month from original pitch date).  [...]

what makes you say that reusing dry yeast is any different than reusing 'wet' yeast? by the time you are reusing I would think that the population is mostly new and those cells that have survived from the original population have used up any reserves given them during the drying process so there should be zero difference at that point.

[The Professor]

My trick question is this.  Are the folks that are just sprinkling the yeast in adjusting their pitching rates?

Nope, there's no need to.  I get great performance from a single rehydrated pack on beers in excess of 1.075.  Statistics are great, but it's performance that counts.

+1000!

[factory]

OK, so I've had results that are all pretty consistent with both dry and liquid yeast.  Starters and no starters for the liquid.  The only thing I haven't ever done is sprinkled.  I think I will try with the next batch and see how it works.

[Three]

Did you read the link to Sean Terrill's experiments?

For anyone who hasn't seen it yet, this is interesting:

http://seanterrill.com/2011/04/01/dry-yeast-viability/

some good info on exactly the effect of water v wort and dry yeast. if you are going after accurate cell count estimates this is the info you need (well actually for accuracy you need the cytometer etc.)

I did.  Interesting data.

[Three]

My trick question is this.  Are the folks that are just sprinkling the yeast in adjusting their pitching rates?

Nope, there's no need to.  I get great performance from a single rehydrated pack on beers in excess of 1.075.  Statistics are great, but it's performance that counts.

Thanks Denny!  I'm in.  The next time I use dry yeast I won't waste half a package!

[anthony]

I could post links to the various theoretical discussions regarding dry yeast rehydrating versus not or I could share real world experience from just a day or two ago... I think everyone should adjust your procedures according to the goals and results you are looking for.

On Monday morning, I pitched 500 grams of US-05 into 174 gallons of 12P wort without rehydrating. I disturbed the surface of the wort after 30 minutes as suggested in Fermentis literature and by 4pm that same day, I had active fermentation at 65F. On Tuesday morning, I pitched 500 grams of US-05 into 187 gallons of 14P wort without rehydrating. I pitched at 55F and 17 hours later when I returned, fermentation was active enough to raise the temperature of the wort to 65F.

Now granted I pitch a little heavy, I am usually in the middle to top end of the Fermentis pitching guidelines of 50-80 grams per hectoliter but I get strong, fast, clean fermentations that attenuate as I would expect. The two batches mentioned above are part of more than 30+ brew sessions in the last 6 months that have all performed that same way.

[kgs]

My trick question is this.  Are the folks that are just sprinkling the yeast in adjusting their pitching rates?

Nope, there's no need to.  I get great performance from a single rehydrated pack on beers in excess of 1.075.  Statistics are great, but it's performance that counts.

Wait... Denny... are you switching parties? ;-) "Quote from: denny on August 25, 2013, 08:35:59 AM  I'm another one who has tried both ways and settled on no rehydration."

[denny]

Nope, just typed it wrong!