Rehydrating yeast

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Rob2010SS

Rob2010SS

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Hey Guys. Got another noob question for you. I see a lot of talk of rehydrating yeast and how it yields some benefits. So I started doing some research on the topic. I pulled up the "spec" sheet for Safale US-05 which is what I used for my grapefruit pulpin. It has a section on there which gives instructions for rehydrating, take a look at the pic. The second option where I have the arrow drawn, sounds like just sprinkling the yeast on the wort and that's it.

So is rehydrating the yeast really necessary if this is what the producer of the yeast recommends?

Capture.JPG
 
Necessary - No. Better - IMO yes. Wort is a harsh environment for the cell walls of the yeast when absorbing moisture. It is often quoted that sprinkling the yeast on the wort will kill up to 50% of the cells. Then the yeast will have to spend energy reproducing before they do most of the fermenting. By pitching the healthier, re-hydrated yeast they can skip the growth phase and start fermenting the wort right away.
 
I genuinely don't see any reason to NOT rehydrate your yeast, really. Even time-wise, I just have it rehydrating while I'm cooling the wort post-boil. I guess you could just pitch it in if you're doing a smaller, lower-ABV batch and you really would have enough yeast cells that way, but even then I'd hazard a guess they yeast aren't performing their best.
 
That's a good point, Shane. I guess I was intimidated a bit by the "process" of rehydrating. Is it really as simple as it sounds?

Am I interpreting the instructions right? "Sprinkle the yeast in 10 times it's weight in sterile water/wort..." The packet of Safale US-05 is 11.5g which would translate to 115g, or just over 4oz of water/wort. Is it really that easy and am I correct in my interpretation of that?
 
Actually although many people are unaware of this, that instruction USED TO APPEAR WITH THE HEADING "Rehydrating with wort" It used to appear in the seperate advanced methods .pdf that Fermentis used to have online... It used to not appear on the packets in the old versions, and that would spark arguments.. but it looks like when they redesign the packaging, and now with even smaller and smaller fonts they fit it onto the packet. Of course many of us probably couldn't see it without glasses. LOL

But it did cause some arguments back in the day. Until some of us posted the .pdf

It is Rehydrating the yeast... only it's rehydrating on top of the wort. Basically, it's sprinkle yeast on top, seal the bucket, let the yeast rehydrate on the wort, wait 30 minutes, then carry it into your brew closet which will help mix the yeast in.


I've said it for years, over a decade... if the instructions specifically come from the yeast lab about their yeasts, then you can confidently follow them.

The people in the yeast LABS who put that on their product are not idiots, they know what they're doing, they know what's best for their product. If that's one of the suggested options, and you want to do so, then follow it.

To me it makes sense to rehydrate on the wort... it instantly acclimates them to what they're supposed to be working with. They wake up instantly surrounded by yummy sugar.. and dive right in.

:mug:
 
Rob2010SS said:
It has to be sterile water, right? Boil it and let it cool? Or can I use tap water?
Click to expand...

Tap water isn't a great idea (even boiled) because of the potential for chloramine in the water, although if you know yours is chlorine/chloramine free, that's not an issue. Easiest is to use a bit of bottled water - it's sanitary enough to not need to be boiled. Just use a StarSan sanitized glass or similar to rehydrate with warmish bottled water. Give it a quick blast in the microwave to warm it and then add the yeast.
 
dyqik said:
Tap water isn't a great idea (even boiled) because of the potential for chloramine in the water, although if you know yours is chlorine/chloramine free, that's not an issue. Easiest is to use a bit of bottled water - it's sanitary enough to not need to be boiled. Just use a StarSan sanitized glass or similar to rehydrate with warmish bottled water. Give it a quick blast in the microwave to warm it and then add the yeast.
Click to expand...

How exact do you need to be with the temp of the water? The instructions say 80*F +/-6*... Do you need to stick to that?
 
From the Fermentis website. Rec is my highlight.

REHYDRATION INSTRUCTIONS:
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 25 to 29°C (77°F to 84°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.

Since they put the rehydration in water before an alternative, I take that as the preferred method.

That said my sprinkled on brews were fine. I just believe in giving my beers the best chance so I rehydrate in water.

My municipal water is very good and apparently low in chlorine or chloramine. I filter with a Brita filter, have never used Campden nor boiled and cooled in rehydration, starters or brewing. Only a charcoal filter. I have also never had any issues.
 
kh54s10 said:
So that would be 74 to 86 degrees. You should be able to get that easily.

Yes, you should be in the temperature range listed.
Click to expand...

I have seen as high as 100F recommended, but yeah, 80±6 F is an easy enough target to hit.
 
To be honest, I don't ever use sterile water, just water out of the tap that's the appropriate temperature. Hasn't turned out bad, yet. I should probably be using sterile water, though.
 
My god people, in what version of the English language where ALTERNATE means "Less than" the other? Seriously?

Have you actually looked at a dictionary?

al·ter·na·tive
ôlˈtərnədiv/
adjective
adjective: alternative

1.
(of one or more things) available as another possibility.
"the various alternative methods for resolving disputes"
synonyms: different, other, another, second, possible, substitute, replacement, alternate; More
standby, emergency, reserve, backup, auxiliary, fallback
"an alternative route"
(of two things) mutually exclusive.
"the facts fit two alternative scenarios"
relating to behavior that is considered unconventional and is often seen as a challenge to traditional norms.
"an alternative lifestyle"

noun
noun: alternative; plural noun: alternatives

1.
one of two or more available possibilities.
"audiocassettes are an interesting alternative to reading"
synonyms: option, choice, other possibility; substitute, replacement
Click to expand...

Where in heaven's name does it say ALTERNATE means one way/version is BETTER than the other???? Alternate means "OPTIONS OF EQUAL VALUE." Two or more DIFFERENT WAYS OF DOING THINGS... not one way better than the other.

I know it's hard for people to accept that the way they do something or believe something may not be the only highway to get to a destination, but geez... butchering the English language to justify it?

SMH
 
I always rehydrate, but I will admit the best beer I've made is a DIIPA with 2 packets of 05 I just sprinkled on top of the wort.
 
Revvy said:
My god people, in what version of the English language where ALTERNATE means "Less than" the other? Seriously?

Have you actually looked at a dictionary?



Where in heaven's name does it say ALTERNATE means one way/version is BETTER than the other???? Alternate means "OPTIONS OF EQUAL VALUE." Two or more DIFFERENT WAYS OF DOING THINGS... not one way better than the other.

I know it's hard for people to accept that the way they do something or believe something may not be the only highway to get to a destination, but geez... butchering the English language to justify it?

SMH
Click to expand...
Yes, I have looked at a dictionary. Alternative doesn't mean "equally good option". Your definition quoted there doesn't say that either. It's just another option that can work. It may be better, equal or worse than the other option.

https://en.oxforddictionaries.com/definition/alternative

It's an alternative because it works OK enough most of the time. OK also doesn't mean "best".

Have you ever read a book on yeast? Seriously, rehydrating in wort is known to be worse than rehydrating in water. Read Yeast by Chris White and Jamil Zainasheff.

That doesn't mean that your beer will fail to ferment if you pitch direct. But you may have a longer growth phase and more stressed yeast.


Reverse your argument. Why on earth would the manufacturers tell you to do a somewhat risky rehydration procedure, with a chance of making their product look bad, if pitching direct was as good?
 
dyqik said:
Yes, I have looked at a dictionary. Alternate doesn't mean "equal". Your definition there doesn't say that either.

http://www.dictionary.com/browse/alternate

Or

https://en.oxforddictionaries.com/definition/alternate

Which refers you to "alternative" for American English.

https://en.oxforddictionaries.com/definition/alternative

It's an alternative because it works OK enough most of the time. OK also doesn't mean "best".

Have you ever read a book on yeast? Seriously, rehydrating in wort is known to be worse than rehydrating in water. Read Yeast by Chris White and Jamil Zainasheff.

That doesn't mean that your beer will fail to ferment if you pitch direct. But you may have a longer growth phase and more stressed yeast.


Reverse your argument. Why on earth would the manufacturers tell you to do a somewhat risky rehydration procedure, with a chance of making their product look bad, if pitching direct was as good?
Click to expand...


yeah, actually I did read it... and STILL I go back to the arguement that the folks at Fermentis are JUST AS KNOWLEGABLE, if not more so about THEIR PARTICULAR YEAST than their competitors....

I keep looking at my medals and all the compliments for my beers from brewers both pro and am, that for the last decade, since I read that .PDF from fermentis, I've still managed to get whilst doing something DIFFERENT than some so called experts may conjecture... AND other homebrewers just keep repeating.

I also remember when Jamil and Palmer were just so adamant that autolysis was going to happen 5 minutes past the moment the yeast was done... UNTIL other people proved that to be incorrect and Palmer admitted he just repeated something he had "heard."

And suddenly years later I came out to be correct in that one too.

I just find it so absurd that some people are so closed minded that they'd actually convince themselves that a company would actually intentionally tell their customers to use the "absolutest worst method possible" in their instructions? Really? you actually believe that, when they had a choice to put a warning NOT to do that.. or just leave it off, they ACTUALLY PUT THAT INSTRUCTION ON THE LABELS?

And the LOGIC behind that is, what? To make their customers make bad beer? SMH

*Shrug*

Brew on. :mug:
 
Reloads with "hot"+P rated kitty food. :)
Seriously, though, one of my friends was using +P without changing his compact .45 recoil spring. The ejected casings came straight back, one with enough force to cut the bridge of my nose when it hit my face.
Fun times.

Regardless of method, may your brews turn out well and always take the advice of Beer Gods with a grain of brewing salts.
 
It is a known fact that sugar kills yeast cells. This is a proven fact. Pitching dry yeast into wort will kill some yeast cells. This does not mean that pitching dry yeast into wort won't make good beer. There are enough cells that you can pitch directly into wort and not worry about the cells that die.

However, it is strange that they would recommend sterile water OR wort for rehydrating. Rehydrating in wort is the same as pitching directly into wort. That doesn't make sense to me.

To me, since it is known that yeast cells die because of sugar, it makes sense to rehydrate in WATER first.
 
Not all yeast cells will die.
If you pitch enough cells, the ones that DO survive will propagate enough healthy yeast to ferment. Under favorable conditions, Fermentis dry yeasts are good quality and one 11.5gram packet generally has more than enough cells to account for minor mistakes of method in 5gallon batches.
 
Lefou said:
Not all yeast cells will die.
If you pitch enough cells, the ones that DO survive will propagate enough healthy yeast to ferment. Under favorable conditions, Fermentis dry yeasts are good quality and one 11.5gram packet generally has more than enough cells to account for minor mistakes of method in 5gallon batches.
Click to expand...

Not sure if this was for me. If so, I never said ALL cells will die. Sugar will kill SOME cells.

I think the key word to take away from what you said is "general". Yes, generally there should be enough yeast but that doesn't mean there always will be. I just don't see why people wouldn't rehydrate.
 
Personally, I will usually re-hydrate dry cells in a solution of water and LME or water and weak wort mixed with Fermaid. I'll do the same with any liquid yeast.

I've suffered at least one lagging fermentation before and realized it was an underpitched starter caused by a poor re-hydration method. The yeast was slow and the lagtime was over 12 hours. Usually I'd get activity sooner, but in this case, this wort had a higher SG than my typical low ABV session ales.
 
Fermentis say that the temperature that you rehydrate at is important. Maybe they've concluded that that's more important than the liquid (at least for relatively low gravity wort) choice, since they recommend rehydration in water or wort before pitching as a tip or trick?
 
To the OP - next time brew a split batch - pitch some with rehydrated X yeast and some with sprinkling it on top and then you can decide for yourself if you see a difference. In all honesty, I think there are a lot of other factors that influence the quality of a beer more so than whether or not the yeast is rehydrated.
 
Lefou said:
Reloads with "hot"+P rated kitty food. :)
Seriously, though, one of my friends was using +P without changing his compact .45 recoil spring. The ejected casings came straight back, one with enough force to cut the bridge of my nose when it hit my face.
Fun times.

Regardless of method, may your brews turn out well and always take the advice of Beer Gods with a grain of brewing salts.
Click to expand...

Ha, this is pretty funny Lefou. I have a .50 Cal desert eagle that if you're holding it just right, the cases come straight back and hit you square in the forehead. I've come home numerous time from the range with what looks like the bottom of a smiley face on my forehead, LOL.

Thanks guys for all of the info. Never meant for this thread to turn into a battle but it's helpful to hear all of the feedback. Hearing and now understanding how rehydrating is done and WHY it's done, I'm less intimidated to try it and see how it goes.
 
A concern I have with dry pitching is the temperature. Fermentis offers the alternative of pitching dry yeast onto the wort, but the wort should be above 68F. I prefer to pitch cooler than that.
 
ncbrewer said:
A concern I have with dry pitching is the temperature. Fermentis offers the alternative of pitching dry yeast onto the wort, but the wort should be above 68F. I prefer to pitch cooler than that.
Click to expand...

I suspect that's most likely why they offer the tip of rehydrating first in a smaller volume of water or wort. You want the yeast to rehydrate warm, then carry out the majority of the growth phase at significantly lower temperatures. That's very hard to do without a cooling loop and heat exchanger in your fermentor.
 
People on Team Rehydrate always like to quote statistics and try to explain the science.

I'm on Team Dry-Pitch for 2 reasons:

1) there is no scientific evidence to suggest that rehydrating yeast creates a better tasting beer (prove me wrong). All the taste tests I've found posted on the Web have found no reliable difference.

2) rehydrating incorrectly or for too long a period can have as many theoretical disadvantages as dry pitching. Sources of contamination, temperature shock, and/or oxygen depletion, to name a few.

And ahem, it is well described that yeast growth is logarithmic, following first order kinetics. During the growth phase the yeast will double every 1-2 hours (or whatever) regardless of how much you pitch. We already take adequate measures to avoid stress during this phase -- oxygenation and temperature control, which should overcome any marginal variance from what we deem to be normal pitching rates, as people have already alluded.

To further complicate matters, we may not even really know how many cells are in the dry yeast packets. Some attempts to determine the validity of the yeast manufacturers' claims have found drastically higher cell counts that indicated.

One more thing, where is the study that suggests there is such a proportionally large decrease in viability when rehydrating in wort as opposed to water? I hope it's not some made-up statistic that has been repeated enough times to be considered fact. Is the proposed decrease in viability honestly due to the components of the wort as everyone seems to think or is it more related to the initial temperature at hydration?

While it is a life or death situation (for the yeast) either way can make good beer.
Meow!
 
RPh_Guy said:
People on Team Rehydrate always like to quote statistics and try to explain the science.

I'm on Team Dry-Pitch for 2 reasons:

1) there is no scientific evidence to suggest that rehydrating yeast creates a better tasting beer (prove me wrong). All the taste tests I've found posted on the Web have found no reliable difference.

2) rehydrating incorrectly or for too long a period can have as many theoretical disadvantages as dry pitching. Sources of contamination, temperature shock, and/or oxygen depletion, to name a few.

And ahem, it is well described that yeast growth is logarithmic, following first order kinetics. During the growth phase the yeast will double every 1-2 hours (or whatever) regardless of how much you pitch. We already take adequate measures to avoid stress during this phase -- oxygenation and temperature control, which should overcome any marginal variance from what we deem to be normal pitching rates, as people have already alluded.

To further complicate matters, we may not even really know how many cells are in the dry yeast packets. Some attempts to determine the validity of the yeast manufacturers' claims have found drastically higher cell counts that indicated.

One more thing, where is the study that suggests there is such a proportionally large decrease in viability when rehydrating in wort as opposed to water? I hope it's not some made-up statistic that has been repeated enough times to be considered fact. Is the proposed decrease in viability honestly due to the components of the wort as everyone seems to think or is it more related to the initial temperature at hydration?

While it is a life or death situation (for the yeast) either way can make good beer.
Meow!
Click to expand...

I'm all for people pitching directly into wort especially with a lower og beer (1.060). What I don't get is why people are fighting the fact that sugar kills yeast. This isn't just a beer thing. Sugar can damage yeast cells and kill the yeast. It won't damage all the cells but it will damage some. If you pitch directly into wort, some cells will die. Please don't read that as direct pitching won't make good beer. I never once said that. All I'm saying is, it is a FACT that sugar can damage some cells which lowers the healthy cell count.

The reason direct pitching still makes good beer is because there are a lot more cells in the packet than the beer actually needs so some damaged cells are ok.

The reason rehydrating is suggested is because dry yeast cell walls can't filter out what is bad for the cells. That's why direct pitching damages some yeast. Rehydrating in sterile water will strengthen the walls which then allows them to filter out the bad (i.e. sugar) so the cells won't get damaged.

Direct pitching is fine as there are enough cells but for me I'd rather not chance it.
 
h22lude said:
I'm all for people pitching directly into wort especially with a lower og beer (1.060). What I don't get is why people are fighting the fact that sugar kills yeast. This isn't just a beer thing. Sugar can damage yeast cells and kill the yeast. It won't damage all the cells but it will damage some. If you pitch directly into wort, some cells will die. Please don't read that as direct pitching won't make good beer. I never once said that. All I'm saying is, it is a FACT that sugar can damage some cells which lowers the healthy cell count.

The reason direct pitching still makes good beer is because there are a lot more cells in the packet than the beer actually needs so some damaged cells are ok.

The reason rehydrating is suggested is because dry yeast cell walls can't filter out what is bad for the cells. That's why direct pitching damages some yeast. Rehydrating in sterile water will strengthen the walls which then allows them to filter out the bad (i.e. sugar) so the cells won't get damaged.

Direct pitching is fine as there are enough cells but for me I'd rather not chance it.
Click to expand...

This 100%. If I only actually need 50-60% of the cells that would be in a packet of yeast, then I'd dry-pitch. But if I need the full cell count (which I most always do), then I rehydrate. In both cases, they still make good beer, it just depends fully on what you need out of the yeast.
 

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