Does rehydrating dried yeast increase lag time?

[eadavis80]

Brewed a batch of Northern Brewer's American wheat ale yesterday. Everything went well - used a wort chiller and pitched the rehydrated Safale US-05 dried yeast to the cooled fermentor. The yeast was rehydrated per the instructions found on the N. Brewer website. Ferm read 70 degrees and still does. Pitched 24 hours ago - no airlock activity. Did aerate the wort with a diffusion stone for 20 minutes prior to pitching and even added yeast nutrient to the yeast solution.

I KNOW airlock activity does NOT = fermentation. That's not my question.

However, when I just sprinkled dried yeast on top of wort and did NOT use a diffusion stone in the past, I think I had airlock activity within 24 hours.

Since I rehydrated (which allegedly is better), used a diffusion stone to increase oxygen and added yeast nutrient, you'd think the yeast would be ready to rock n' roll.

Do any of you have any experience with rehydrating dried yeast causing an INCREASE IN LAG TIME? It seems my yeast should be happier than ever - not lazy and inactive.

 

[Hello]

I've never had that increase lag time. Quite the opposite. You pitched at 70 but what did you rehydrate at? You sure your water wasn't too hot? Maybe the yeast was a little stressed.

Also, I thought you didn't need more than a minute or so to aerate using a oxygen system. What was your OG?

 

[eadavis80]

I rehydrated at about 80, if that.

And, I AERATED the wort - it wasn't straight oxygen with oxygen tank. It was an AERATION system powered by a high-powered aquarium pump, not a disposable oxygen tank you'd get at a hardware store. Those I know take only a minute or two, aeration is about 20 minutes, according to its directions.

OG was modest - only like 1.040.

 

[mblanks2]

I've never had a lag when rehydrating. Usually just the opposite. I typically have activity within 8 - 24 hours. Not sure what you've got going on. What was the date on the yeast package?

 

[eadavis80]

I don't have the date, but it was just shipped earlier in the week from N. Brewer. The package was discarded at the house we brewed at yesterday. I can't fathom the dried yeast was bad. Hopefully fermentation signs pick up by day's end.

 

[Hammy71]

I've never noticed a difference...so I don't bother rehydrating. It's a sore subject around here to say the least. As with a lot of things in life....if it's the way you do it, you think it's best. I wouldn't fret about the yeast, it will do it's thing. Just give it time.

 

[boydster]

I'm not sure why it happens sometimes, but a longer lag than usual does seem to happen every once in a while even with rehydrated yeast. Read around, and you'll see lots of folks also have long lags when they don't rehydrate, so I don't think the hydration is the issue. I was just listening to a Basic Brewing podcast yesterday where they had Sean Terrill on the show and they did an experiment on hydrated vs. dry pitched yeast (US-05). In one of the tests, they had the dry pitched yeast take off a little faster than the hydrated. If you have a chance, listen to the show and you can draw your own conclusions, but the interesting part to me as it relates to your post was that they encountered the same issue you are encountering with one of the tests. I wouldn't worry too much at this point. It sounds like you did everything right, so just give it a little time and the yeast will probably do just fine.

 

[BigFloyd]

I've had somewhat longer (about 25-50% more hours) lag times for the batches that I sprinkled dry into the wort.

80*F or less rehydration water seems a bit on the cool side. Suggestions vary on the temp of the tap water to be used. Based on all of the info out there, I follow Dr. Cone's advice and rehydrate in 100*F +/- 5*F filtered tap water. The slurry is usually around 85-88*F after the 20 min has elapsed, so I do have to attemperate it by adding small doses of the cooler wort (60-62* for an ale) with a turkey baster until I can get it to within less than 15*. If you skip that step, you may temperature shock the cells which would likely up the lag time.

I also get much longer lag on ciders using ale yeast (Nottingham being the favorite) vs. beers no matter if I rehydrate or not.

 

[eadavis80]

I meant when I sprinkled the dried yeast to the water - THAT WATER was right around 105, but by the time I added the yeast solution to the ferm, that yeast solution was around 80 degrees. I'm guessing it'll be okay. If I don't see any airlock activity, WHICH I KNOW DOES NOT NECESSARILY MEAN FERMENTATION, but it has correlated with fermentation in every other batch I've ever done, THEN I'll be more concerned. It's probably no big deal.

 

[benco]

105 seems to high for rehydrating. I usually below 90.

 

[BigFloyd]

105 seems to high for rehydrating. I usually below 90.

Nope. From an interview with Dr. Clayton Cone (yeast microbiologist):

Let me give you some facts regarding rehydration and you can decide for
yourself where you want to compromise.
Every strain of yeast has its own optimum rehydration temperature. All of
them range between 95 F to 105F. Most of them closer to 105F. The dried
yeast cell wall is fragile and it is the first few minutes (possibly
seconds) of rehydration that the warm temperature is critical while it is
reconstituting its cell wall structure.

As you drop the initial temperature of the water from 95 to 85 or 75 or 65F
the yeast leached out more and more of its insides damaging the each cell.
The yeast viability also drops proportionally. At 95 – 105 F, there is
100% recovery of the viable dry yeast. At 60F, there can be as much as 60%
dead cells.

The water should be tap water with the normal amount of hardness present.
The hardness is essential for good recovery. 250 -500 ppm hardness is
ideal. This means that deionized or distilled water should not be used.
Ideally, the warm rehydration water should contain about 0.5 – 1.0% yeast
extract

For the initial few minutes (perhaps seconds) of rehydration, the yeast
cell wall cannot differentiate what passes through the wall. Toxic
materials like sprays, hops, SO2 and sugars in high levels, that the yeast
normally can selectively keep from passing through its cell wall rush right
in and seriously damage the cells. The moment that the cell wall is
properly reconstituted, the yeast can then regulate what goes in and out of
the cell. That is why we hesitate to recommend rehydration in wort or
must. Very dilute wort seems to be OK.

We recommend that the rehydrated yeast be added to the wort within 30
minutes. We have built into each cell a large amount of glycogen and
trehalose that give the yeast a burst of energy to kick off the growth
cycle when it is in the wort. It is quickly used up if the yeast is
rehydrated for more than 30 minutes. There is no damage done here if it is
not immediately add to the wort. You just do not get the added benefit of
that sudden burst of energy. We also recommend that you attemperate the
rehydrated yeast to with in 15F of the wort before adding to the wort.
Warm yeast into a cold wort will cause many of the yeast to produce petite
mutants that will never grow or ferment properly and will cause them to
produce H2S. The attemperation can take place over a very brief period by
adding, in increments, a small amount of the cooler wort to the rehydrated
yeast.

 

[eadavis80]

So add the dried yeast to water between 90-105 and then after a little bit cool that solution to within 15 degrees of your wort. In any event, I seem to have strong fermentation kicking now - the airlock is moving about 2 x's per second or so.

 

[hopdropper]

Glad to see this post this morning cause I just started wondering the same thing. I sprinkled DRY for the last couple years, aerated with a venturi tube, and didn't really bother controlling the fermentation temperature (beyond the thermostat in the closet set at 65). Never had much of an issue...decent beer, average 12 hour lags.
This winter I started to rehydrate, oxygenate with a 60 second blast of pure O2, and control temps in a proper fermentation chamber. So far I've seen a wide array of lag times with the rehydrated yeast...from 4 hours to 24 hours. For instance, I brewed and imperial stout last week. Rehydrated two packs of S-04 in a covered mason jar with tap water cooled to about 90*F. When I was just about done chilling the wort, I added a turkey baster full of 70 degree wort to the jar. 15 minutes later when I pitched, the jar was bubbling over with krausen! Needless to say, I had VIGOROUS fermentation in probably 4 hours in the carboy...plus full blow-off in under 24.
Now fast-forward to last night. Robust porter, same process, one pack rehydrated US-05...zero activity in the mason jar, and so far this morning, ZERO apparent activity in the carboy. Going on 12 hour lag.
Glad I'm not the only one having the same issue. I'll keep an eye on that porter today...

 

[eadavis80]

As a golfer and beer brewer (not great at either, but LOVE doing both) I have come up with an analogy. Pitching yeast (or brewing a batch period) is just like a golf swing - so many variables and so many ways to have bad results. You think you're doing the right thing every time, but the results vary - even if you're using the same ingredients. I guess every batch is its own entity just like no two holes of golf played (even if they're the same hole on different days) are the same.

Good luck with that porter.

 

[hopdropper]

hooray for live yeasties. 18 hours post-pitch in the porter and there was the slightest layer of krausen. now 24 hours in, a solid 1/2 inch layer and plenty of bubbles in the blow-off bucket. your analogy is spot-on. patience also plays a big role, and i don't have much of that when it comes to beer!

 

[eadavis80]

Yup - like golf, the two hobbies have taught me some patience. It's still something I have to work on, but it's like an employee at my local home brew shop once said. "You're at the mercy of the yeast. Make 'em happy and you'll be happy. You work on their terms. Yeast are just like women - temperamental."

 

[skw]

I remember reading that rehydrating yeast gives you a higher count of viable cells and that dry yeast does not require aerated wort. Lag time has never been a high priority for me, pitching rate is what I put more emphasis on. I rehydrate, or if I forget to, I pitch two packets of dry yeast. From my limited brewing experience, I like to think that keeping an eye on pitching rate and temperature was what improved my brewing the most.

 

[BigFloyd]

From my limited brewing experience, I like to think that keeping an eye on pitching rate and temperature was what improved my brewing the most.

And you are 100% on the money.

 

[wilserbrewer]

Bobby M did a pretty good write up on this a long while ago. IIRC, the increased lag time is due to the oxygenated wort. I think the yeast need to consume the available oxygen, the begin fermentation, or the growth phase is longer???


Wilserbrewer
Http://biabbags.webs.com/

 

[Steelers77]

I've recently used US-05 twice and in both instances I did a Hydrated vs dry pitch and in each case the hydrated took around 36 hours to see active fermentation vs the dry pitch which took ~12-16hrs for active fermentation. Do you know what lot your US-05 was from?

 

[tooldudetool]

I'm not sure why you guys wouldn't be following the rehydration instructions from fermentis: http://www.fermentis.com/brewing/homebrewing/product-range/
They say 05 should be rehydrated in 80 degree water, + or - 6 degrees. 100 degree water is way too hot...

 

[Seriuqs]

I just used US-05 this last weekend on a batch of Graff and it took off the quickest I have seen in recent history. I did not re-hydrate because the directions on the packet it came in said: "Sprinkle directly into wort". I remember this standing out to me because I normally re-hydrate per the package instructions.

Perhaps it is supposed to be sprinkled in dry?

My yeast did not come from Northern Brewer btw.

 

[boydster]

I'm not sure why you guys wouldn't be following the rehydration instructions from fermentis: http://www.fermentis.com/brewing/homebrewing/product-range/
They say 05 should be rehydrated in 80 degree water, + or - 6 degrees. 100 degree water is way too hot...

100F water isn't hot enough to do any damage to the yeast. Yeast loves warm temperatures, up to about 110 before it becomes stressful. According to Dr. Clayton Cone, 95-105 is an ideal temperature range for rehydrating dry yeast. When I have asked Fermentis about their instructions, they swear that you don't do any harm by hydrating at 80 with their yeast. That may be perfectly true. Still, biologically, the yeast are not going to experience any negative impact (and may actually benefit) from being hydrated at 100F.

Perhaps it is supposed to be sprinkled in dry?

No. The data sheets describe proper rehydration procedures. It's been shown under a microscope repeatedly that hydrating in wort (this is what you are doing when you sprinkle the yeast into the wort) results in substantially lower viability than hydrating in water. Here's a great experiment done by Sean Terrill with US-05 to test hydration and viability: http://seanterrill.com/2011/04/01/dry-yeast-viability/

And I'll also refer back to the Basic Brewing episode I posted earlier... Again, Sean Terrill was a part of that along with the regular hosts. They tested US-05 hydrated in water, pitched dry, and double-pitched dry to simulate the pitch rate of the properly hydrated yeast. Instead of counting cells as the basis for the result of that experiment, though, they sampled the resulting beers and drew conclusions from those - probably more relevant our purposes than just the cell counts alone. Here's the link again: http://traffic.libsyn.com/basicbrewing/bbr07-28-11hydration.mp3

 

[hopdropper]

just pulled the empty US-05 packet from the trash. i'm assuming the bottom line of numbers is the expiration date...04...2015. the top line reads 87384...120...0704.

 

[eadavis80]

That fermentation podcast was brutally slow to listen to. I think I would have rather watched the airlock on my primary for the hour-plus than listen to that thing. I endured it until about the 16-minute mark. ONly at that time did they even BEGIN do discuss their findings about the pitch dry vs. rehydration experiment. Have you listened to the entire thing? If so, what were their findings? That podcast could have been so much more focused and told me what I needed to know in 5 minutes tops. From what I gathered in the over quarter hour I listened to though was that their studies contradicted other findings on yeast cell health on pitching dry vs. rehydrating and the people on the show were in disagreement about which beers they preferred. Once I heard that, I kind of figured it's like everything else in home brewing - people are going to do what they prefer/what they've had success with in the past. They're going to share that knowledge with others when asked in an effort to help. But at the end of the day I don't think this "argument" - like many, for example "to secondary or not to secondary" will ever have a conclusive "right answer." My yeast are doing their thing so in this case I had an overall good experience rehydrating and aerating my wort for 20 minutes before pitching my yeast solution. The yeast solution sprinkled on top of water that was around 100 degrees. It was then cooled to about 80 and pitched. It worked for me, so that's what I'll stick with until I run into further problems. Thanks all.

 

[tektonjp]

No one has mentioned the fact he added nutrient to his hydration water. For my money, that would upset the balance for yeast health and cause a lag. The nutrient would best be put into the boil, not the rehydration water.

 

[Calichusetts]

I don't know if its due to my small batch size but I don't rehydrate and nearly every beer I've ever made has taken off in under 8 hours. I usually brew at night and pitch around 11-12pm. By 7AM I have some layer of foam, every time. I've always been puzzled by the "up to 36 hours" idea around here. It wasn't until I used liquid that I saw a lag time over 24 hours.

I put yeast nutrient in the boil, but here is a question/possible explanation: since dry pitching seems to kill 30% of the yeast, I tend to overpitch by about 20%

Am I actually overpitching or underpitching?

A good example would be if I needed 10 grams of yeast, should I pitch 12-13 grams without rehydrating?

 

[boydster]

That fermentation podcast was brutally slow to listen to. I think I would have rather watched the airlock on my primary for the hour-plus than listen to that thing. I endured it until about the 16-minute mark. ONly at that time did they even BEGIN do discuss their findings about the pitch dry vs. rehydration experiment. Have you listened to the entire thing? If so, what were their findings? That podcast could have been so much more focused and told me what I needed to know in 5 minutes tops. From what I gathered in the over quarter hour I listened to though was that their studies contradicted other findings on yeast cell health on pitching dry vs. rehydrating and the people on the show were in disagreement about which beers they preferred. Once I heard that, I kind of figured it's like everything else in home brewing - people are going to do what they prefer/what they've had success with in the past. They're going to share that knowledge with others when asked in an effort to help. But at the end of the day I don't think this "argument" - like many, for example "to secondary or not to secondary" will ever have a conclusive "right answer." My yeast are doing their thing so in this case I had an overall good experience rehydrating and aerating my wort for 20 minutes before pitching my yeast solution. The yeast solution sprinkled on top of water that was around 100 degrees. It was then cooled to about 80 and pitched. It worked for me, so that's what I'll stick with until I run into further problems. Thanks all.

You couldn't be bothered with listening to it so you want someone else to give you the run down? Ok, but if you want to hear what my impression of the show was, you are still getting the information from my frame of reference and not your own.

They discussed the fact that they did a hydration experiment using water vs wort in the past and doing cell counts. Yeast hydrated in wort was substantially less viable. Sean then made the same wort and fermented it 3 ways. One with a pitch rate of .75 million cells/ml/°P of hydrated 05, one pitched with an equal amount by weight of unhydrated 05 resulting in an actual pitch rate of .34 million cells/ml/°P, and one with roughly double the unhydrated 05 to get to an actual pitch rate of .75 million cells/ml/°P. They did a blind tasting and made notes on their impressions of each beer.

They all agreed that beer made with the hydrated yeast was cleaner. They differed in how much they preferred it, with Sean saying he picked up more off flavors from both of the unhydrated - estery flavors from the one with the lower pitch rate and yeast autolysis characteristics from the one with the bigger pitch, probably due to the excess dead yeast (his presumption, not mine).

The end result is that pitching the right amount of hydrated yeast makes better beer. The debate is about how much better.

 

[eadavis80]

Thanks Boydster - concise and to the point. You summarized in a few short paragraphs what took them over an hour to address.

Now, about yeast nutrient - you guys put that in the BOIL?! Why wouldn't you put yeast nutrient with the YEAST SOLUTION you're re-hydrating? That's what Northern Brewer suggests. I don't claim they're the be-all / end-all of home brewing, but they have been a reliable source of info in my limited experience.

 

[boydster]

I don't use it often, and never with dry yeast since it comes packaged with nutrients already and the wort you are pitching it into should be pretty nutritious (unless you are using a ton of adjuncts). I sometimes use it in my starters, especially if it's older yeast, and those times I add it to the starter wort just before the end of the boil.

 

[Calichusetts]

wyeast's nutrient blend says to dissolve it in water then add around 10 minutes left in the boil. I didn't even know this, just noticed it in recipes, often in boil. Especially with high gravity ales

 

[boydster]

Thanks Boydster - concise and to the point. You summarized in a few short paragraphs what took them over an hour to address.

Now, about yeast nutrient - you guys put that in the BOIL?! Why wouldn't you put yeast nutrient with the YEAST SOLUTION you're re-hydrating? That's what Northern Brewer suggests. I don't claim they're the be-all / end-all of home brewing, but they have been a reliable source of info in my limited experience.

I was just thinking more about this. You don't mean GoFerm, by any chance, do you? That would go in the rehydrating water.