How many don't rehydrate their yeast?

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kombat said:
I'm not sure - but his statements in "Yeast" don't claim that liquid yeast is universally superior to dry, but rather simply that sprinkling dry yeast directly into wort can reduce viability by up to 50%. If he were seeking to discredit competition, I'd expect him to take a position that portrays liquid yeast as superior to dry in all cases, rather than simply telling you how to get the most out of your dry yeast (that he doesn't even sell).
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You have a point there, but it can have the effect of knocking dry yeast manufacturers down a peg or two. Perception only of course. I don't mean to whack the beehive but its fun to ponder these things. :mug:
 
I tend to just sprinkle the dry yeast onto the foam (after splash aerating, there's quite a bit of foam)

Everything seems to turn into beer.
 
rhys333 said:
You have a point there, but it can have the effect of knocking dry yeast manufacturers down a peg or two. Perception only of course. I don't mean to whack the beehive but its fun to ponder these things. :mug:
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Completely disagree. Why would it have the effect of knocking them down a peg or two? If you read his advice correctly,

"If you are working with dry yeast, determining how much to pitch is relatively easy. Most dry yeast contains about 7 billion to 20 billion cells per gram, depending on the cell size and other nonyeast material, but that is not the number of viable cells per gram you will have once you rehydrate yeast. That depends on a number of factors, such as storage and rehydration techniques. Find out from your supplier how many viable cells per gram you can expect (which might be as low as 5 billion), then simply divide the number of cells needs by the number of viable cells, and you will know the weight in grams of dry yeast need. Of course, this assumes all the yeast is active and that you properly rehydrate it following manufacturer's recommendations before pitching. Failure to rehydrate dry yeast properly will result in the death of approximately half the cells."

This is an aside when talking about how to figure out your viable cell count in slurries and in liquid yeast vials. He goes into great detail about how to determine that, and talks about some less complicated ways to figure it out, but for the most part shows how complex it can really be. Then he states how easy it is to figure out the cell count for dry yeast. Which would make it sound more like an endorsement for using dry yeast because you know how much yeast to expect in the pack. Never does he say, "Oh but then with dry yeast you have to take the extra 10-15 minutes to rehydrate it. How lame is that?" He simply says, follow the manufacturer's advice in how to rehydrate properly, and you'll easily have the amount of viable yeast cells you're expecting.

He has absolutely no financial incentive to convince people to rehydrate. In fact, quite the opposite. If he finds out that people are thinking they're pitching approximately 200b cells, and in fact his studies are showing that 100b of those are dying off by dry-pitching, he has EVERY incentive to keep his mouth shut. He should want people to keep under-pitching, in the hopes that they will produce lower quality beer, and he can then point to exact studies about his own yeast and how many viable cells to expect, and how much more reliable his yeast is compared to dry yeast.

It helps to play the devil's advocate with actual logical arguments.

As far as my opinion on the matter, I'll just reiterate what others have said:
1) Even Safale says you can do both. Which leads me to believe that they likely know something about rehydration, but want to make the ease-of-use of their product appealing.
2) Anecdotal evidence of people under-pitching, yet still creating good beer will never trump evidence from the guy who runs his own yeast lab. Never.
3) It's so simple and easy, I just don't see why people would skip it.
 
bierhund said:
Orders of magnitude would come into play once cell division comes into play. Losing half your cells due to shock will cause the lag phase to take longer. The shock from the high sugar (relative) environment causes heat shock proteins to turn on. This can potentially cause issues in fermentation. I think in a small batch/low gravity beer, these effects are unnoticed because there still is plenty of cells to get the job done. Dry yeast provides the most cells out of all the ways to use yeast. That being said, I would bet that if the yeast was properly rehydrated, it could handle larger batches / higher gravity ales. It would be a neat experiment. I like to think of it like this, "How would I like to be woken up from a deep sleep? Gently with a warm cup of coffee and breakfast cooking or with a pail of ice cold water?" I know which method is going to start my day better lol
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Why will this cause the lag time to be any more than the time it takes for the yeast cells to reproduce, thus doubling the amount of cells. It would seem like the difference in time would be a matter of minutes rather than hours.
 
RM-MN said:
Why will this cause the lag time to be any more than the time it takes for the yeast cells to reproduce, thus doubling the amount of cells. It would seem like the difference in time would be a matter of minutes rather than hours.
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You got it. I took particular interest in modern physics in college as an engineer and 2x is exactly one cell reproduction. Yeast acts a lot like quantum physics... (But yeah. It is observable, I get that) If the dry pitch causes all or a lot of mutants I would say that is an issue. But clearly almost exactly no one has ever said a dry pitched dry yeast beer tastes significantly worse.. So.. I am thinking.. Overall.. Meh.. I still like seeing a proof though.. ;)

Fred
 
RM-MN said:
Why will this cause the lag time to be any more than the time it takes for the yeast cells to reproduce, thus doubling the amount of cells. It would seem like the difference in time would be a matter of minutes rather than hours.
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That's under the assumption that the yeast are healthy and have a perfect doubling reproduction event. The shock creates unhealthy yeast and wort though delicious is not technically considered a perfect environment.
 
So, for the folks that argue against secondary because of the risks of infection, do you argue not to rehydrate for the same? For what it's worth, I'm a relative rookie (entering my third year of brewing) and have done it both ways with success, but I do tend to prefer liquid yeast as i think the bad batches I've made have have all been with dry yeast, the worst 2 were Nottingham rehydrated with properly boiled then cooled water.
 
I'm still not convinced. He doesn't cite any studies or anything, he just says 'it will kill half the yeast'.

I know he knows more than me, but something that definitive should have some evidence you can point at.
 
UndeadFred said:
You got it. I took particular interest in modern physics in college as an engineer and 2x is exactly one cell reproduction. Yeast acts a lot like quantum physics... (But yeah. It is observable, I get that) If the dry pitch causes all or a lot of mutants I would say that is an issue. But clearly almost exactly no one has ever said a dry pitched dry yeast beer tastes significantly worse.. So.. I am thinking.. Overall.. Meh.. I still like seeing a proof though.. ;)

Fred
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Amen brother.
 
When I began brewing, I pitched dry because it was simple. After some long lagtimes and many google searches like "Why isn't my wort fermenting?" I started rehydrating and now my beers take off like a shot!

I am converted. Rehydrating is even easier and more satisfying than rdwahahb.
 
I'm speculating the US-05 rehydration instruction let you know that you can dry pitch if you really want too because otherwise everyone would buy the other brand. Certainly doesn't mean its best practice.

Also, rehydration speeds up brew night because you don't have to wait for half an hour after you pitch.

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.
 
moreb33rplz said:
I'm still not convinced. He doesn't cite any studies or anything, he just says 'it will kill half the yeast'.

I know he knows more than me, but something that definitive should have some evidence you can point at.
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Read "Yeast." According to biologists much smarter than me, the problem is that until the yeast cells are rehydrated, they're unable to regulate the amount of sugars passing across their membrane, which can lead to autolysis. Once they're rehydrated with plain water, they're much better able to regulate sugar uptake across their membrane.

Or something like that. I trust the guy with the multi-million dollar yeast company and the Ph.D.
 
I've done both and didn't see much of a difference. For the beer I'm brewing tomorrow I'll probably rehydrate if I remember to have the sterile water ready in time.
 
I find my fermentations kick off much faster when I rehydrate the yeast. I also don't bother with "sterile" water, I just use water straight from my tap, mixing the hot and cold until I get the target temperature (85° F). However, I'm on municipal water, so our water is treated for sanitation. If you're on well water, you should probably continue with a boil and cool protocol.
 
I re-hydrate, it's a good excuse for me to use my diy stir plate to "Gently stir for 30 minutes...".
 
kombat said:
Read "Yeast." According to biologists much smarter than me, the problem is that until the yeast cells are rehydrated, they're unable to regulate the amount of sugars passing across their membrane, which can lead to autolysis. Once they're rehydrated with plain water, they're much better able to regulate sugar uptake across their membrane.

Or something like that. I trust the guy with the multi-million dollar yeast company and the Ph.D.
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I've got the book. He just doesn't give any detail, and I'm sure there is more too it than 'half of them die every time'.

My guess is that certain strains, certain conditions, etc, all have an effect, and the worst case scenario is that half of the cells die.
 
kombat said:
I find my fermentations kick off much faster when I rehydrate the yeast. I also don't bother with "sterile" water, I just use water straight from my tap, mixing the hot and cold until I get the target temperature (85° F). However, I'm on municipal water, so our water is treated for sanitation. If you're on well water, you should probably continue with a boil and cool protocol.
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Or if you have heavy chlorine/chloramines in your tap water. Those things are made to kill stuff just like our little yeastie-beastie friends.

:)
 
I've never re-hydrated, nor have I ever made a starter. Dry yeast has always worked great and if my reclaimed yeast has been in the fridge more than a month, I just pitch two mason jars.
 
joshesmusica said:
I have a question for all those who never rehydrate:

How many BJCP judged competitions have you won with those beers?
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I'll count them up momentarily.....

EDIT:

1st place - 0
2nd place - 3
3rd place - 2

I'll also say that I might not be the best brewer, only three 1st places in my career so far (two with liquid yeast, and one a wild ferment with nothing pitched!), but I do have nearly 20 awards total. It makes sense to me that about 1/4 of my awards were from non-rehydrated dry yeast, as I use dry yeast about that often. I've yet to win a Best of Show, but I have recently achieved Second Best of Show (liquid yeast in this case).

http://brixies.bobbo.net/brixtoberfest/

The point is, to the naysayers, it doesn't seem to make any difference whether you use dry or liquid, rehydrated or not. Make a couple of batches side by side if you want. You either won't be able to taste a difference, or, as some experiments have shown, you might even prefer the non-rehydrated one!!!
 
dmtaylor said:
I'll count them up momentarily.....



EDIT:



1st place - 0

2nd place - 3

3rd place - 2



I'll also say that I might not be the best brewer, only three 1st places in my career so far (two with liquid yeast, and one a wild ferment with nothing pitched!), but I do have nearly 20 awards total. It makes sense to me that about 1/4 of my awards were from non-rehydrated dry yeast, as I use dry yeast about that often. I've yet to win a Best of Show, but I have recently achieved Second Best of Show (liquid yeast in this case).



http://brixies.bobbo.net/brixtoberfest/



The point is, to the naysayers, it doesn't seem to make any difference whether you use dry or liquid, rehydrated or not. Make a couple of batches side by side if you want. You either won't be able to taste a difference, or, as some experiments have shown, you might even prefer the non-rehydrated one!!!
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Nice! I really wasn't asking to sound cynical, just to clarify, I'm actually interested what the results are, as that's the only thing that's really important obviously. And the bjcp is an important clarification, as I've been around a couple of non judged comps and the winners were more about popularity contest (either they had more friends there, were more sanguine and friendly than the others, or it was a popular style) than anything.

Are there more out there who have won under bjcp competitions without rehydrating?

One more point of discussion, or at least a follow-up to this discussion is, if we know that we are losing around 50% of the viable yeasts with a direct pitch, and yet bjcp qualified judges aren't able to pick up any off-flavors, then maybe it's time to start doing more in-depth studies into pitch count. If ~100b cells are getting the job done without creating to many off-flavors, then why do all the calcs suggest 200b at the moment (numbers just thrown out there obviously). Are the yeast just that much healthier than when the calcs were designed?
 
joshesmusica said:
If ~100b cells are getting the job done without creating to many off-flavors, then why do all the calcs suggest 200b at the moment (numbers just thrown out there obviously). Are the yeast just that much healthier than when the calcs were designed?
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Calculators are calculators. They are developed by humans, inherently flawed, who make conservative judgments. I've heard it repeated many times now that the standard yeast calculators are overly conservative and you don't need to use as much as they say. Maybe half as much will suffice. Maybe one third. Maybe one eighth! Play around and see what works. In the case of dry yeast, we can afford to sacrifice half the population with no ill effects. I also usually see a very fast start with dry yeast, faster than with liquid. Non-rehydrated. It's worth experimenting.
 
ncbrewer said:
What was your pitching temperature, if you remember? I ask because Fermentis instructions say pitch at 68F or higher, which is the main reason I rehydrate.
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I don't know how this is relevant, but... I also cannot answer your question, unfortunately. Pitch temperature is the one variable that I have not tracked carefully over the past 16 years. I need to start doing that -- thanks for the reminder. What I can tell you is that *typically* -- not always, but typically -- I leave my wort to cool down the last 30 degrees or so (from about 90 or 100 F or whatever) overnight or over many hours, and delay pitching until temperatures have gone below 70 F, for ales. For lagers, I would never pitch until temperature got down to around fermentation temp, around 50 F plus or minus a couple degrees, and in that case, the W-34/70 is the only dry lager yeast I have ever had good success with personally. Pitch rate for that yeast would be two packs for 5 gallons instead of just the usual one pack for ales. Still takes off like the dickens within about 24 hours. Average score I have achieved so far with that yeast is a 37 -- pretty tasty.
 

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