Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: sparkleberry on August 25, 2013, 02:01:11 AM

Title: dry yeast question
Post by: sparkleberry on August 25, 2013, 02:01:11 AM
so i brewed two days ago. ground water wouldn't get me to pitching temps, which is fine as i planned on letting wort chill the rest of the way in the ferm chamber anyway. and i did.

i rehydrated yeast yesterday and nothing was happening after 24 hours+.

today i sprinkled another pack of us05 into the wort and have very good things going on now.

i rehydrated the yeast at 105. followed reliable directions for it and still had nothing. it's an american wheat similar to gumballhead(which i've never actually had). within a few hours of pitching dry yeast today, fermentation is taking off.

i guess my question is, did i do the right thing? i've never rehydrated yeast before. i usually use wyeast 1056 and make a starter, but was a little confused as to why fermentation didn't take off with the rehydrated us05. brew day was off a little as i haven't brewed in a while but process was still pretty solid.

cheers and thanks.
Title: Re: dry yeast question
Post by: HoosierBrew on August 25, 2013, 02:22:54 AM
I used to rehydrate per the instructions, but i have just sprinkled on top for years and won't go back.  It's easy when rehydrating to  1/ go a little warm and kill some or all of the yeast   or  2/ to add another sanitation risk.  I don't know how accurate your thermometer is, but it sounds like either a bad/old packet of yeast, or the actual temp you rehydrated at was a little high and you killed the yeast, especially since the packet of dry kicked fermentation right off. Use it dry, man.
Title: Re: dry yeast question
Post by: erockrph on August 25, 2013, 02:46:56 AM
I used to rehydrate per the instructions, but i have just sprinkled on top for years and won't go back.  It's easy when rehydrating to  1/ go a little warm and kill some or all of the yeast   or  2/ to add another sanitation risk.  I don't know how accurate your thermometer is, but it sounds like either a bad/old packet of yeast, or the actual temp you rehydrated at was a little high and you killed the yeast, especially since the packet of dry kicked fermentation right off. Use it dry, man.

+1 - I've tried it both ways and didn't notice an appreciable difference, so I just sprinkle it on dry.

105 does seem like a high temp for rehydrating. The Fermentis website recommends 80F water if you choose to rehydrate. It could be that either your water outright killed the yeast from being too hot, or you ended up shocking the rehydrated yeast by taking them from 100+ degree water and pitching it into much cooler wort.
Title: Re: dry yeast question
Post by: majorvices on August 25, 2013, 11:09:16 AM
I never rehydrate. For high gravity beers I add extra yeast (as much as 50% more). Always have fermentation within 24 hours and narry a hitch. Just no need to rehydrate US-05 in my experience. None. Nada. Zilch. Don't let anyone tell you differently.
Title: Re: dry yeast question
Post by: kgs on August 25, 2013, 02:32:44 PM
I went back and forth for years, but several batches ago had a contaminated batch (my 2nd in over 4 years of brewing, the first happened on my 2nd batch) and my process is otherwise so good I'm going back to sprinkling. I don't see any difference in lift-off and if I were worried about it one bit I'd sprinkle another half-packet. Make sure you have fresh yeast and keep it in the fridge until brewday.

Without knowing your temps, I concur you may have killed your yeast. The persnickety process of ensuring the rehydration water was within the right range is probably where I introduced contamination.
Title: Re: dry yeast question
Post by: denny on August 25, 2013, 03:35:59 PM
I'm another one who has tried both ways and settled on no rehydration.
Title: Re: dry yeast question
Post by: breweite on August 25, 2013, 04:10:14 PM
I just wanted to be clear, as I'm switching to more and more dry yeast for $ reasons. Just "sprinkle" and walk away?  I've sometimes sprinkled and then shook or used my drill to give it a good swirl.  Is this a bad idea?
Title: Re: dry yeast question
Post by: denny on August 25, 2013, 04:21:20 PM
It's unlikely to be harmful, but it won't help either.  Just sprinkle and walk away is all that's necessary.
Title: Re: dry yeast question
Post by: sparkleberry on August 25, 2013, 04:25:32 PM
thanks everyone.
Title: Re: dry yeast question
Post by: Stevie on August 25, 2013, 04:40:08 PM
I don't mind rehydrating my dry yeast. I simply boil a small amount of water in a flask covered with foil and let cool while brewing. If I ever use dry yeast as a backup plan, I pitch right on top the wort.
Title: Re: dry yeast question
Post by: repo on August 25, 2013, 05:04:23 PM
so i brewed two days ago. ground water wouldn't get me to pitching temps, which is fine as i planned on letting wort chill the rest of the way in the ferm chamber anyway. and i did.

i rehydrated yeast yesterday and nothing was happening after 24 hours+.

today i sprinkled another pack of us05 into the wort and have very good things going on now.

i rehydrated the yeast at 105. followed reliable directions for it and still had nothing. it's an american wheat similar to gumballhead(which i've never actually had). within a few hours of pitching dry yeast today, fermentation is taking off.

i guess my question is, did i do the right thing? i've never rehydrated yeast before. i usually use wyeast 1056 and make a starter, but was a little confused as to why fermentation didn't take off with the rehydrated us05. brew day was off a little as i haven't brewed in a while but process was still pretty solid.

cheers and thanks.

I have done both and not found any discernible difference. I haven't rehydrated in years, but when I did it was as per Fermentis 80 +/- 6 degrees.  I have also never had dry yeast take of within a few hours, always several hours and later. I think your original pitch was starting to work.

I have also tried the starter vs straight vial and found no discernible difference. There are lots of situations where making a starter is not necessary, just as there are lots of situations where making one is necessary. 

Title: Re: dry yeast question
Post by: narcout on August 26, 2013, 04:40:48 AM
I doubt temperature was your issue, unless your thermometer is not accurate.

Chris White and/or Jamil (not sure who wrote the section on working with dry yeast in Yeast) recommend rehydrating at 105 degrees.  I've rehydrated many a packet of US-05 at that temperature and never had a problem with it.

Perhaps rehydrating isn't necessary, but it's never killed my yeast.
Title: Re: dry yeast question
Post by: Jimmy K on August 26, 2013, 03:49:01 PM
I just wanted to be clear, as I'm switching to more and more dry yeast for $ reasons. Just "sprinkle" and walk away?  I've sometimes sprinkled and then shook or used my drill to give it a good swirl.  Is this a bad idea?
I think some of the idea behind sprinkling is to allow the cells to more slowly rehydrate as they sit on top. Immediately stirring may cause the cells to fill with sugary wort faster. I can't say it's bad, but maybe it's not good.
Title: Re: dry yeast question
Post by: aveteto01 on August 26, 2013, 04:12:42 PM
I'm another one who has tried both ways and settled on no rehydration.

So, Rehydrated < Dry

But is a yeast starter better than just sprinkling the dry yeast in? Or is that really just to boost pitching rate for higher OG beers?

Title: Re: dry yeast question
Post by: In The Sand on August 26, 2013, 04:44:27 PM

I just wanted to be clear, as I'm switching to more and more dry yeast for $ reasons. Just "sprinkle" and walk away?  I've sometimes sprinkled and then shook or used my drill to give it a good swirl.  Is this a bad idea?
I think some of the idea behind sprinkling is to allow the cells to more slowly rehydrate as they sit on top. Immediately stirring may cause the cells to fill with sugary wort faster. I can't say it's bad, but maybe it's not good.

I used to sprinkle and walk away, but since I got my Blichmann plate chiller I can chill to pitching temps right away. So I fill the carboy half way then pitch the dry yeast as I fill the rest of the way. Still seeing attenuation as expected and no ill effects in the flavor department. YMMV
Title: Re: dry yeast question
Post by: Three on August 26, 2013, 04:56:49 PM
I'm another one who has tried both ways and settled on no rehydration.

So, Rehydrated < Dry

But is a yeast starter better than just sprinkling the dry yeast in? Or is that really just to boost pitching rate for higher OG beers?

Confusing I know.

I'm not sure if it's less.  This is just a group of brewers that in their experiences (and opinions), if you sprinkle it in/on dry, it works and saves you an extra step and the fermentation is good.  I too have done both and have had good results either way.  (If it was the best way I don't know, but the beer tasted good.)  I usually rehydrate because that's what the manufacturer says to do, and for me it's easier to pour into my carboy.  If/when I use a bucket, sprinkling the yeast on top would be easy.  I think the confusion comes from what the manufacturer says to do, compared to the practice of many accomplished brewers (of which I'm not one yet).  Bottom line is it's your brewhouse, and your the brewmaster, try brewing one each way and see what happens......
Title: Re: dry yeast question
Post by: In The Sand on August 26, 2013, 05:06:08 PM
I'm another one who has tried both ways and settled on no rehydration.

So, Rehydrated < Dry

But is a yeast starter better than just sprinkling the dry yeast in? Or is that really just to boost pitching rate for higher OG beers?

Confusing I know.

I'm not sure if it's less.  This is just a group of brewers that in their experiences (and opinions), if you sprinkle it in/on dry, it works and saves you an extra step and the fermentation is good.  I too have done both and have had good results either way.  (If it was the best way I don't know, but the beer tasted good.)  I usually rehydrate because that's what the manufacturer says to do, and for me it's easier to pour into my carboy.  If/when I use a bucket, sprinkling the yeast on top would be easy.  I think the confusion comes from what the manufacturer says to do, compared to the practice of many accomplished brewers (of which I'm not one yet).  Bottom line is it's your brewhouse, and your the brewmaster, try brewing one each way and see what happens......

+1 Great advice!
Title: Re: dry yeast question
Post by: denny on August 26, 2013, 06:15:52 PM
I'm another one who has tried both ways and settled on no rehydration.

So, Rehydrated < Dry

But is a yeast starter better than just sprinkling the dry yeast in? Or is that really just to boost pitching rate for higher OG beers?

A yeast starter is not only unnecessary, but can even be detrimental with dry yeast.
Title: Re: dry yeast question
Post by: scottNU on August 26, 2013, 06:40:42 PM
I usually rehydrate because that's what the manufacturer says to do, and for me it's easier to pour into my carboy. 

I have normally rehydrated dry yeast simply because I didn't have a good way to get the yeast into the carboy through the neck.  To be honest, I didn't try sprinkling down the hole because I imagined it would either stick to the neck or stick to the sanitized funnel. 

Does anyone has a nice trick to get the powedered yeast into the carboy or am I way overthinking this point?
Title: Re: dry yeast question
Post by: bazowie on August 26, 2013, 06:58:01 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Title: Re: dry yeast question
Post by: anthony on August 26, 2013, 07:20:16 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Is this a trick question? The instructions you posted not only suggest that you can use wort instead of water for rehydration but they also suggest that you can rehydrate directly in the fermenter.
Title: Re: dry yeast question
Post by: morticaixavier on August 26, 2013, 07:24:42 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Is this a trick question? The instructions you posted not only suggest that you can use wort instead of water for rehydration but they also suggest that you can rehydrate directly in the fermenter.

also, have you considered trying to get professional pitch packages? it would probably save you money at that scale. Or reusing/propogating.
Title: Re: dry yeast question
Post by: Jimmy K on August 26, 2013, 07:25:17 PM

Does anyone has a nice trick to get the powedered yeast into the carboy or am I way overthinking this point?
Overthinking perhaps. I cut the top off the packette, squeeze it so it forms a V shaped funnel, pour through carboy neck onto wort. It piles in the middle a bit and takes a little longer to saturate - and a few grains stick to the neck - but it works.
 
Generally - I pitch straight in with lower OG beers and rehydrate for higher OG beers where I'm more concerned with pitching rate.
Title: Re: dry yeast question
Post by: morticaixavier on August 26, 2013, 07:27:33 PM
I usually rehydrate because that's what the manufacturer says to do, and for me it's easier to pour into my carboy. 

I have normally rehydrated dry yeast simply because I didn't have a good way to get the yeast into the carboy through the neck.  To be honest, I didn't try sprinkling down the hole because I imagined it would either stick to the neck or stick to the sanitized funnel. 

Does anyone has a nice trick to get the powedered yeast into the carboy or am I way overthinking this point?

the best trick I have found is to sprinkle the dry yeast on about a cup of warm pre-boiled water and wait till it... oh... nevermind.

If you have been rehydrating for that reason you should go ahead and keep doing it. or get some buckets.
Title: Re: dry yeast question
Post by: scottNU on August 26, 2013, 07:58:28 PM
I usually rehydrate because that's what the manufacturer says to do, and for me it's easier to pour into my carboy. 

I have normally rehydrated dry yeast simply because I didn't have a good way to get the yeast into the carboy through the neck.  To be honest, I didn't try sprinkling down the hole because I imagined it would either stick to the neck or stick to the sanitized funnel. 

Does anyone has a nice trick to get the powedered yeast into the carboy or am I way overthinking this point?

the best trick I have found is to sprinkle the dry yeast on about a cup of warm pre-boiled water and wait till it... oh... nevermind.

If you have been rehydrating for that reason you should go ahead and keep doing it. or get some buckets.

Fair enough.  Not worth worrying about. Go forth and propagate little yeasty friends.
Title: Re: dry yeast question
Post by: narcout on August 26, 2013, 08:30:40 PM
For anyone who hasn't seen it yet, this is interesting:

http://seanterrill.com/2011/04/01/dry-yeast-viability/
Title: Re: dry yeast question
Post by: bazowie on August 26, 2013, 10:33:51 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Is this a trick question? The instructions you posted not only suggest that you can use wort instead of water for rehydration but they also suggest that you can rehydrate directly in the fermenter.

also, have you considered trying to get professional pitch packages? it would probably save you money at that scale. Or reusing/propogating.
I would but i only brew every  1-1/2 to 2 months and I use us-05 pretty much always, and there is no way to store a 500g brick so I just use the packets and rehydrate.
Title: Re: dry yeast question
Post by: bazowie on August 26, 2013, 10:35:31 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Is this a trick question? The instructions you posted not only suggest that you can use wort instead of water for rehydration but they also suggest that you can rehydrate directly in the fermenter.
It was a trick question (not really) just that is tells you how to rehydrate with 80deg water
Title: Re: dry yeast question
Post by: Three on August 26, 2013, 11:35:15 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Is this a trick question? The instructions you posted not only suggest that you can use wort instead of water for rehydration but they also suggest that you can rehydrate directly in the fermenter.
It was a trick question (not really) just that is tells you how to rehydrate with 80deg water

+1 on the temperature!

And +1 on how many more packages needed dry verses re-hydrated......

My trick question is this.  Are the folks that are just sprinkling the yeast in adjusting their pitching rates?
Title: Re: dry yeast question
Post by: HoosierBrew on August 26, 2013, 11:50:47 PM
People say there is no reason to rehydrate, if this is true why does the Safale website have these instructions?

(Rehydration Instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.)

I rehydrate per the instructions and have never had a problem and I dont have to spend the extra for more packs, (32 gallon ferment at a time), I rehydrate (7) packs instead of pitching 11-12 packs dry.

Is this a trick question? The instructions you posted not only suggest that you can use wort instead of water for rehydration but they also suggest that you can rehydrate directly in the fermenter.
It was a trick question (not really) just that is tells you how to rehydrate with 80deg water

+1 on the temperature!

And +1 on how many more packages needed dry verses re-hydrated......

My trick question is this.  Are the folks that are just sprinkling the yeast in adjusting their pitching rates?
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.
Title: Re: dry yeast question
Post by: Three on August 27, 2013, 12:36:57 AM
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.


Title: Re: dry yeast question
Post by: HoosierBrew on August 27, 2013, 12:58:31 AM
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.
Title: Re: dry yeast question
Post by: majorvices on August 27, 2013, 01:10:59 AM
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. 
Title: Re: dry yeast question
Post by: Three on August 27, 2013, 01:25:41 AM
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......
Title: Re: dry yeast question
Post by: morticaixavier on August 27, 2013, 02:42:44 PM
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.)
Title: Re: dry yeast question
Post by: denny on August 27, 2013, 02:57:53 PM
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.
Title: Re: dry yeast question
Post by: ynotbrusum on August 27, 2013, 10:19:59 PM
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.
Title: Re: dry yeast question
Post by: morticaixavier on August 27, 2013, 10:34:55 PM
[...] 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.
Title: Re: dry yeast question
Post by: The Professor on August 28, 2013, 12:17:05 AM
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!
Title: Re: dry yeast question
Post by: factory on August 28, 2013, 12:26:27 AM
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.
Title: Re: dry yeast question
Post by: Three on August 28, 2013, 12:34:48 AM

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.
Title: Re: dry yeast question
Post by: Three on August 28, 2013, 12:40:58 AM
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!
Title: Re: dry yeast question
Post by: anthony on August 28, 2013, 01:24:51 PM
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.
Title: Re: dry yeast question
Post by: kgs on August 28, 2013, 02:53:51 PM
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."
Title: Re: dry yeast question
Post by: denny on August 28, 2013, 03:48:06 PM
Nope, just typed it wrong!
Title: Re: dry yeast question
Post by: narcout on August 28, 2013, 07:05:04 PM
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.

To me that actually sounds like a pretty good reason to rehydrate. 

I've done it both ways and never noticed a difference in performance.  However, I've never performed the infamous blind triangle tasting either.
Title: Re: dry yeast question
Post by: beersk on August 28, 2013, 08:14:22 PM
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.

To me that actually sounds like a pretty good reason to rehydrate. 

I've done it both ways and never noticed a difference in performance.  However, I've never performed the infamous blind triangle tasting either.
I think he was possibly being sarcastic. I rehydrate always now. It's easier to pour into a carboy and it's better for yeast health. Do whatch you want.
Title: Re: dry yeast question
Post by: ynotbrusum on August 29, 2013, 10:06:39 AM
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.

To me that actually sounds like a pretty good reason to rehydrate. 

I've done it both ways and never noticed a difference in performance.  However, I've never performed the infamous blind triangle tasting either.
I think he was possibly being sarcastic. I rehydrate always now. It's easier to pour into a carboy and it's better for yeast health. Do whatch you want.

Not really sarcastic, because I think it works either way, so I agree with those who choose not to do so, but I prefer to do so, for the reason stated - cell wall stabilization and proven greater viability.  When I said "reuse of dry yeast is trickier" I just meant that it is trickier than simply repitching the entire yeast cake - i.e., trickier than the initial question of whether to rehydrate or not.
Title: Re: dry yeast question
Post by: thatgeekguy on August 29, 2013, 05:12:28 PM
I'm in the rehydration camp, no big deal and feel it helps the yeast assimilate better. Just saw an interesting article on an easy way to rehydrate using Rubbermaid containers that I'll try on my next batch:
http://www.homebrewfinds.com/2013/08/step-by-step-rehydrating-dried-yeast.html