Re-hydrate the yeast or sprinkle it on?

Hello everyone,

First post here, making my first batch: A Canadian Red Ale extract /w dry yeast package.

I am trying to make the best beer possible and am willing to do the extra steps to do so. I have been reading numerous instructions on the best ways to brew and one thing that I am not sure of is how to pitch the yeast.

There seems to be two methods:
1) Re-hydrate the yeast for 15 minutes until fermenting. Poor into fermentor and stir.
2) Sprinkle the yeast onto the top of the wort in the fermentor and do not disturb.

What is the generally accepted best way of pitching the yeast?

I never rehydrate, but that's just my experience. I'm not sure if there is a generally accepted method, but here's a good thread regarding your question:

https://www.homebrewtalk.com/f13/rehydrating-dry-yeast-not-necessary-62514/

Awesome, thanks for the link mac,

Gonna go with the sprinkle method for this batch.

I typically just follow directions on the pack. If I remember correctly, I think SafAle says to just sprinkle it on the wort. Danstar recommends rehydrating. Pretty sure the difference would be negligible either way.

Good luck!

I normally sprinkle on top of cooled wort and do not stir. I've read that its advisable to try and avoild letting it "clump up" so I tend to sprinkle the yeast as evenly as I can on the top of the wort.

I use to sprink it on in a bucket then pour into a carboy for extra airation with great results

there was a podcast epidsode last month on basic brewing about this topic. it was an experiment on two batches one sprinkle, one rehydrated.

If you have a. d. d. like me I will summarize. The science show that yeast has more viability if you rehydrate. The tasting showed that they couldn't agree on any one method tasting better. They did agree rehydrating may help with bigger beers.

Personally, I just sprinkle. Hasn't failed me yet and I am not introducing another step that could lead to infection.

Rehydrate it helps the yeast with the shock of going on to the wort. More yeast cells will live if you rehydrate.

If you are cold pitching into 62* wort and rehydrating at 85*, how does this not shock the yeast?

LKABrewer I don't think they mean thermal shock... they are referring to the dry yeast re-hydrating and water and other wort materials moving across the yeasts cell walls. When re-hydrated in warm water the cells have a better chance of not being destroyed during this process.

I've re-hydrated and just sprinkled on top of the wort. I believe in MY experience that fermentation takes place a little bit faster when the yeast are re-hydrated (and when you make a starter). I would recommend re-hydrating for big beers as suggested as you need a much higher overall cell count to ferment correctly and completely.

Yes and check this guys site for pitching rates. http://www.mrmalty.com/pitching.php

Treat you yeast right! They do all the hard work

Many would argue that sprinkling it on IS a form of rheydrating...Including the fermentis website.

I stopped yeast proofing in a seperate container years ago. In fact fermentis yeasts on their website, actually say that their yeast can be sprinkled or even rehydrated on wort (including the surface of the beer) there are lots threads discussing this, as I mentioned above. It's one of those debates like aluminum vs stainless, or Ag vs extract where it may not truly. There was a recent discussion about that here, https://www.homebrewtalk.com/f163/two-packs-safale-us-05-vs-rehydrating-198654/#post2318350

Here is some of that discussion;

AZ_IPA said:

I agree with ya Bob, but I tend to be a "directions" type of guy and at least US-05 says to sprinkle into wort.

If I do that, I have one less thing to clean up later

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Revvy said:

I agree. That's what I've been doing for years, since I read THAT on the fermentis website in their "tips and tricks" section years ago and I've been doing it ever since. I sprinkle on the surface of the fermenter seal up my fermenter, let it sit on the surface for 15-30 minutes while I begin clean up and then I move it into my brew closet. And since 90% of what I brew is with safale 05, and I get great scores and comments on beers, I'm not going to stop doing it that way. Some will, of course, argue differently, but I maintain that that is "rehydrating with wort" only not is a separate container. If you can rehydrate it in a small container of "sterile wort" then you can do it in a 5 gallon container of wort as well.

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Bob said:

It's weird how they say different things in different places. Huh.

Anyway.

Bob

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= revvy] And that's why I think the argument is silly because the differences in doing it an not are probably insignificant, at least on the homebrew scale.

But this is what it says in the current version of the tips.

Water or Wort?
Fermentis yeast can be rehydrated with sterile water or sterile wort.
Whatever media is chosen it is compulsory to assure its sterility.
After the wort has been boiled for at least 15 minutes collect the volume
required for rehydration and leave to cool to the required temperature.
Rehydrate the yeast for 30 minutes.

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I'm just not doing it in a smaller container.

And even on this pdf. It says sprinkling http://www.fermentis.com/FO/pdf/HB/EN/Safale_US-05_HB.pdf

Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry yeast in 10 times its own weight of sterile water or wort at 27C ± 3C (80F ± 6F). Once the expected weight of dry yeast is reconstituted into cream by this method (this takes about 15 to 30 minutes), maintain a gentle stirring for another 30 minutes. Then pitch the resultant cream into the fermentation vessel.
Alternatively, pitch dry yeast directly in the fermentation vessel providing the temperature of the wort is above 20C (68F). 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 and then mix the wort e.g. using aeration.

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That's why it's a silly argument nowadays....(like most of them)

I think the yeast can figure out what to do on it's own.

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That's just an FYI for you, that it isn't all that cut and dried these days where the rehydrate argument stands.

There really should be no debate of any kind: follow the manufacturer's instructions. Look on their website for full instructions (might be more detailed than on the package). If the circumstances call for rehydrating (just pitched some W-34/70 last weekend under conditions that required rehydrating) then do so.

osagedr said:

there really should be no debate of any kind: Follow the manufacturer's instructions. Look on their website for full instructions (might be more detailed than on the package). If the circumstances call for rehydrating (just pitched some w-34/70 last weekend under conditions that required rehydrating) then do so.

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+1

I rehydrate 100% of the time, and doubt I'll ever do otherwise. I've not looked into it myself, but Jamil repeatedly says that if you just sprinkle in the dry yeast you could kill up to 50% of the yeast. Even if he's overestimating the kill rate, why risk it? Yeast really needs water to just build up the cell walls and wake itself up. Yeast isn't good at regulating what it's taking in right away, so while you're rehydrating it by sprinkling into the wort, the yeast is also pulling in lots of other stuff it doesn't need.

One thing that really annoys me is the difference in directions between what they give the homebrewer versus the commercial brewer. The homebrew packages of yeast tend to say to just sprinkle on the wort. But for commercial breweries, they stress rehydrating the exact same yeast for optimal performance. It's like they just expect homebrewers to fudge it up.

Rehydrating only takes like 30 minutes, and you can start it rehydrating while you're cooling your wort and such, so I see no reason NOT to do it.

shanecb said:

I rehydrate 100% of the time, and doubt I'll ever do otherwise. I've not looked into it myself, but Jamil repeatedly says that if you just sprinkle in the dry yeast you could kill up to 50% of the yeast. Even if he's overestimating the kill rate, why risk it? Yeast really needs water to just build up the cell walls and wake itself up. Yeast isn't good at regulating what it's taking in right away, so while you're rehydrating it by sprinkling into the wort, the yeast is also pulling in lots of other stuff it doesn't need.

One thing that really annoys me is the difference in directions between what they give the homebrewer versus the commercial brewer. The homebrew packages of yeast tend to say to just sprinkle on the wort. But for commercial breweries, they stress rehydrating the exact same yeast for optimal performance. It's like they just expect homebrewers to fudge it up.

Rehydrating only takes like 30 minutes, and you can start it rehydrating while you're cooling your wort and such, so I see no reason NOT to do it.

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I agree overall but it does increase the risk of infection when performed inconsistently.

I have always re-hydrated my yeast with some water 80-85 degrees. I sprinkle the yeast on the water then cover it with saran wrap. After about 20 minutes, I stir the yeast into the water then recover. It starts to bubble and foam allot. I add it to my cooled wort, and aerate the mes out of it with an electric whisk for 5 minutes. This has always given me great results. Good Luck!

BradleyBrew said:

I agree overall but it does increase the risk of infection when performed inconsistently.

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I don't buy this argument at all. If you can't rehydrate yeast in water without getting an infection you don't stand much of a chance of making good beer anyway.

BradleyBrew said:

I agree overall but it does increase the risk of infection when performed inconsistently.

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I rehydrate, but the easy way:

1. While you are brewing (say, during the mash, while milling, etc) put a tupperware container with some water (8 oz.) into the microwave. I put a top on mine, loosely. Hit 2:00
2. When you start chilling, grab that container and add your dry yeast.
3. Pitch when ready.

It's that easy.

I just sprinkle on top of the wort. But since I do only 1.5 gallon batches I have plenty of yeast to workwith.

sketerbuck said:

I don't buy this argument at all. If you can't rehydrate yeast in water without getting an infection you don't stand much of a chance of making good beer anyway.

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Whatev... to a newbie starting out I would recommend to just rip it and pitch it... once you are comfortable with your sanitation practices then do whatever your want... it can lead to an infection if not done correctly. Just just one more area to introduce something. Its not an argument its a fact. Its another step that is not necessarily beneficial to making better beer.

zyx345 said:

I normally sprinkle on top of cooled wort and do not stir. I've read that its advisable to try and avoild letting it "clump up" so I tend to sprinkle the yeast as evenly as I can on the top of the wort.

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Learn something new everytime i read the threads.

I have done the sprinkle method without any issues. I have now moved over to liquid yeast. Makes it a little easier

How do you rehydrate the yeast in the vials

I do a split boil on my stovetop. Since I collect the first runnings mostly in one pot, and the rest in the other, I end up with two vastly different worts which I then combine in the fermenter. Since worts of different densities are basically like oil and water, the lighter wort sits on top. I figure it's such a low gravity that it's basically like rehydrating the yeast by just sprinkling it on.

Never had any off flavors, incomplete attenuations, or any problems doing this.

BradleyBrew said:

Whatev... to a newbie starting out I would recommend to just rip it and pitch it... once you are comfortable with your sanitation practices then do whatever your want... it can lead to an infection if not done correctly. Just just one more area to introduce something. Its not an argument its a fact. Its another step that is not necessarily beneficial to making better beer.

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"Skipping rehydration kills about half the cells piched. Besides having only half as much yeast as is needed, the dead cells immediately begin to break down and affect the beer flavor."
-Yeast, by Chris White and Jamil Zainasheff (page 146)
I do understand your point about recommendations for new brewers, but rehydrating your yeast will be beneficial to your beer.

I made beer for over a year with the sprinkle on top method, never had problems, read here that was bad, now i rehydrate, still never had problems, But Im "fairly" sure that the ones i rehydrate kick off in the same evening, I cant remember the "sprinkle" ones starting so fast.

I feel like you get beat up around if you say you direct pitch dry yeast.

Just my 2p - I havnt noticed any real difference between rehydration and dry. Dry seems easier - less time fiddling so less crap in the beer. Suits me.

sketerbuck said:

"Skipping rehydration kills about half the cells piched. Besides having only half as much yeast as is needed, the dead cells immediately begin to break down and affect the beer flavor."
-Yeast, by Chris White and Jamil Zainasheff (page 146)
I do understand your point about recommendations for new brewers, but rehydrating your yeast will be beneficial to your beer.

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Not that Chris and Jamil don't know their stuff, but "kills about half the cells" ? This gets thrown a lot around without any cited sources to back it up. I get that the yeast cells cannot properly control what passes through their membrane and that the sugary wort is not the best thing for them. I also listened to the podcast where Jamil talks about following the recommendations given to COMMERCIAL and not HOMEBREWERS for dry yeast. Well, guess what ? The instructions on the fermentis website for all their strains specifically calls for either sterile water OR wort. They also specify you can pitch directly if the wort is above 20C.

I personally always rehydrate ever since my second run in with bad notty, just to proof it, so I have no ax to grind. It's just that I see the 50% quoted all the time and it seems arbitrary to me.

jfr1111 said:

Not that Chris and Jamil don't know their stuff, but "kills about half the cells" ? This gets thrown a lot around without any cited sources to back it up.

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Chris White is the source, IMO. I guess it's understood that anything that guy says is backed by science.

jfr1111 said:

Not that Chris and Jamil don't know their stuff, but "kills about half the cells" ? This gets thrown a lot around without any cited sources to back it up. I get that the yeast cells cannot properly control what passes through their membrane and that the sugary wort is not the best thing for them. I also listened to the podcast where Jamil talks about following the recommendations given to COMMERCIAL and not HOMEBREWERS for dry yeast. Well, guess what ? The instructions on the fermentis website for all their strains specifically calls for either sterile water OR wort. They also specify you can pitch directly if the wort is above 20C.

I personally always rehydrate ever since my second run in with bad notty, just to proof it, so I have no ax to grind. It's just that I see the 50% quoted all the time and it seems arbitrary to me.

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I agree 100%. I hydrate sometimes.. other times I just pitch.. typically depending on gravity. I just don't understand why some brewers have to get on their "high horse" about re-hydrating... if it works for you fine.. If direct pitching results in good beer for the individuals that goes that route that's fine too. Its always a different % off yeast this is off'ed when added directly to the wort blah, blah, blah. As I mentioned before if someone is just starting then direct pitch. Once you are accustomed to sanitizing then go for rehydrating or yeast starters, etc.

Just because I scientist says something doesn't mean its a scientific law. "Scientist" once believed the world was flat. Even though Dr. Chris is a multi millionaire from cultivating yeast.

passedpawn said:

Chris White is the source, IMO. I guess it's understood that anything that guy says is backed by science.

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That very well might be, but it doesn't change the fact that a company that actually manufactures dry yeast has rehydration protocols using wort in their datasheets. Danstar specifically says not to use wort, because of loss of viability. But they still don't give percentages... Does it changes with OG ? Temperature ? Strain ? Is it always "about half" ? This is what I'm wondering about.

jfr1111 said:

That very well might be, but it doesn't change the fact that a company that actually manufactures dry yeast has rehydration protocols using wort in their datasheets. Danstar specifically says not to use wort, because of loss of viability. But they still don't give percentages... Does it changes with OG ? Temperature ? Strain ? Is it always "about half" ? This is what I'm wondering about.

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+ 1 agreed... just stating "50%" is a very vague arbitrary figure. Thats like saying rehydrating yeast will yield 100% of all viable yeast in a packet.... I'm sure some yeast do not survive the rehydration process.

It seems intuitive that more yeast cells would survive water rehydration vs wort rehydration; however, I will agree with above posts that I would like to see more data before I believe the 50% theory. From my own experience both ways will work.

Although I do rehydrate in water to error on the side of caution.

The only time I pitch dry yeast is in a low gravity beer like with a 1.035 mild with nottingham. Then I wash that to keep a stock of the yeast in my fridge. Even if the cells die, I would still be pretty close to a good pitching rate. At the same time I always keep a packet on hand in case a starter fails. So I donot have any emotion invested to either side, but have a question along the lines of others in this thread.

I would also like to see what the 50% figure is based on...if a packet is 80% viable (meaning 10% died in dehydration, storage, shipping, handling, etc) then is that 10% that is already dead factored into the 50%? So with the 50% figure are you saying you would have only 40% of what is viable in the packet? Or still 50% of what is viable.

Man, the question in my head is a lot harder to explain than I thought!

Dry yeast contains so many cells per gram that pitching dry usually has no ill effects even though many of the cells are killed off. The time when there would be a noticeable difference is a very high gravity beer, where pitching dry would result in underpitching, and rehydrating would help keep pitching rates within range.

jfr1111 said:

Not that Chris and Jamil don't know their stuff, but "kills about half the cells" ? This gets thrown a lot around without any cited sources to back it up..........
Does it changes with OG ? Temperature ? Strain ? Is it always "about half" ? This is what I'm wondering about.

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One oft cited source is a study performed by Dr Clayton Cone who is or was the lead biologist for Lallemand. Rehydration temperature was found to have a profound effect on viability, sometimes lowering to only 40% when using 60F water as opposed to 100% with the reccomended 95-105F water. The higher the OG the more concentrated the sugars passing through the cell walls are, and the more damaging it is to the yeast. To what degree, I don't remember. I have heard that Dr Charles Bamforth who heads the Master Brewer program at UC Davis has also done some studies with similar results, but I can not confirm this.

BradleyBrew said:

Thats like saying rehydrating yeast will yield 100% of all viable yeast in a packet.... I'm sure some yeast do not survive the rehydration process.

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According to the studies by Dr Clayton Cone 100% was pretty easy to achieve using fresh yeast as long as the water temp was within the 95-105F range. To stress, this was using FRESH yeast, dry yeast viability decreases ~4%/year if stored at fridge temp, and ~20% /year if stored at room temp. I'm sure you're right that "some" cells die since we're dealing with billions of cells, but if rehydrated properly it should be an insignificant amount.

If I'm fermenting in a carboy then I rehydrate just because every time I try to sprinkle it in dry I always get some on the neck of the carboy and I'm worried that could eventually cause an infection.

When I ferment in a bucket I don't bother though.