US-05 Rehydrating and Proofing

I'm not seeing any bubbles or foam after rehydrating and proofing some US-05. Could it be a bad packet?

BlakeL said:

I'm not seeing any bubbles or foam after rehydrating and proofing some US-05. Could it be a bad packet?

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Not likely. How long ago did you pitch it.

What is your procedure for rehydrating? Temps, etc... I use the 05 exclusively and have not had any troubles recently. Do you have the lot number and date code as well?

I haven't pitched it yet. I just started brewing.

cl330b said:

What is your procedure for rehydrating? Temps, etc... I use the 05 exclusively and have not had any troubles recently. Do you have the lot number and date code as well?

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I let it sit for 15m in about 95 degree water and then added a teaspoon of sugar in room temperature water that I boiled in half the water earlier. I think I have a total of about 1 cup of liquid.

Hi Blake,

Some older homebrewing books or instructions might suggest "proofing the yeast" (proving the yeast?) but that's not how we roll these days... :rockin:

There's really no need or reason to proof homebrewing yeasts any longer. They are prepared and packaged in a much different manor these days (since the 90's I'd guess). They're all ready for the race once you open the packet!

Pitching the yeast into 95F water and adding sugar is actually likely to hurt the little buggers. Rehydrating the yeast (at a lower temp) before use might be helpful, check the package and see what the instructions say?

Unless you have an exceptionally old package of yeast or maybe a damaged packet (not properly sealed) just pitch and forget.

- Mike
[an old-timer whom also once proofed yeast but has seen the light]

BlakeL said:

I let it sit for 15m in about 95 degree water and then added a teaspoon of sugar in room temperature water that I boiled in half the water earlier. I think I have a total of about 1 cup of liquid.

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yeah, don't do that. just re hydrate and pitch.

Arguably the hydration temperature is high. 90 is what many people recommend. some yeast packets say 80 or 85 on them. But that probably isn't an issue.

The data sheet for S-05 says this:

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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Don't rehydrate just pitch it.

eastoak said:

yeah, don't do that. just re hydrate and pitch.

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... or just pitch. The beer will start in a reasonable amount of time (active ferment in 6-8 hours typically) anyway and will finish the same. I have used dried yeast at home and commercially and have seen no proof that rehydrating makes a notable difference in the finished beer. Between the extra steps and added risk of contamination (small though they be) I would rather keep it simple; pitch and done.

FWIW, in a commercial vessel I dump the dry yeast in through the manway before xfering the aerated wort into the ferm. AT home, I dump it into the bottom of my fermenting bucket shortly before I pour the wort in.

wailingguitar said:

... or just pitch. The beer will start in a reasonable amount of time (active ferment in 6-8 hours typically) anyway and will finish the same. I have used dried yeast at home and commercially and have seen no proof that rehydrating makes a notable difference in the finished beer. Between the extra steps and added risk of contamination (small though they be) I would rather keep it simple; pitch and done.

FWIW, in a commercial vessel I dump the dry yeast in through the manway before xfering the aerated wort into the ferm. AT home, I dump it into the bottom of my fermenting bucket shortly before I pour the wort in.

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The bottom of my carboy is wet with starsan so would feel pretty uncomfortable re-hydrating the dry yeast in starsan residue before adding the wort. Probably doesn't matter, but I always pour the yeast on top of the wort, not the other way around.

I do re-hydrate but never felt it really made much difference and am glad to see a professional feels the same way.

brewit2it said:

The bottom of my carboy is wet with starsan so would feel pretty uncomfortable re-hydrating the dry yeast in starsan residue before adding the wort. Probably doesn't matter, but I always pour the yeast on top of the wort, not the other way around.

I do re-hydrate but never felt it really made much difference and am glad to see a professional feels the same way.

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I follow you with the puddle of star san thing... I use iodophor and tip my bucket a few times to make sure it is pretty well all drained out. Even if there is a wee bit left it is on the outside where the level is lower, I dump the yeast in the center and it stays dry. Sprinkling on top is fine, it works... all else being equal though, I do like to pour onto it (or in the case of a unitank, pump into it) because it gives an instant mixing. Not a major deal, of course.

You will find that probably half or more of commercial breweries that use dry yeast don't bother with rehydrating.

wailingguitar said:

I follow you with the puddle of star san thing... I use iodophor and tip my bucket a few times to make sure it is pretty well all drained out. Even if there is a wee bit left it is on the outside where the level is lower, I dump the yeast in the center and it stays dry. Sprinkling on top is fine, it works... all else being equal though, I do like to pour onto it (or in the case of a unitank, pump into it) because it gives an instant mixing. Not a major deal, of course.

You will find that probably half or more of commercial breweries that use dry yeast don't bother with rehydrating.

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That's awesome man. I guess it begs the question though, are these breweries where we would actually want to drink the beer?

I'm 90% convinced re-hydrating is a waste of time so will probably go back to just pitching on top of the wort like I did when I first started. Anything that makes my brew day easier is exactly my style.

someone here stated that by pitching directly into the wort, about half the yeast dies because of osmotic pressure - cell walls have not all had a chance to reconstitute themselves before the sugar comes rushing in. i seem to remember this was from a reputable source, but can't recollect who... so might be hard scientific fact, or a repeated wives' tale.

<dubbel post>

Yeah, that discussion was linked to in another thread, but here's the actual discussion:

http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/

I'm finishing a rye stout right now and have a packet of US 05 on the counter. I might rehydrate, but probably not.

prpromin said:

Yeah, that discussion was linked to in another thread, but here's the actual discussion:

http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/

I'm finishing a rye stout right now and have a packet of US 05 on the counter. I might rehydrate, but probably not.

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That's a good link. Interesting that optimum temp is 105F!! Looks like the OP was right on target with his 95 degree temp. Shoot, now I just swung back to 80% likely to keep rehydrating

sweetcell said:

someone here stated that by pitching directly into the wort, about half the yeast dies because of osmotic pressure - cell walls have not all had a chance to reconstitute themselves before the sugar comes rushing in. i seem to remember this was from a reputable source, but can't recollect who... so might be hard scientific fact, or a repeated wives' tale.

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I've heard that too... it was discussed on the thread another poster linked. I also read an article that interviewed Dr Cone (I'll see if I can find the link) where he said 'up to' 60% viability 'can' be lost. I usually rehydrate for that reason, but I've dry pitched 05, 04, and Notty and noticed no difference from when I've rehydrated. It doesn't seem to matter these days, what with yeast quality and packaging, but I still rehydrate most all the time when using dry. Better safe than sorry.

Edit: Here's the link to the interview with Dr. Cone.

Sweetcell; That is a good and fair question. Chris White has discussed the fact that, yes, dry yeast will lose some viability when not hydrated... I believe, I can't say for certain, but I believe he was trying to make it sound like dry yeast weren't quite as handy as they are made out to be... remember, he has a business to run and products to market (I do not know for certain that this was his aim in making the statements, but it is possible and has been suggested by others elsewhere). Others have shown the same result... what is usually ignored, however, is that the cells that don't survive become, basically, "yeast nutrient" and serve as energizer for the cells that survive... Net result, you have less viable yeast to start with BUT they have a ready made energizer thrown into the mix. Regardless, the beers pitched this way will have (depending on strain) an average of 8 hours (I have seen as little as 6 as much as 9) before an active ferment is noticed. There's nothing wrong with that at all!

Brewit2it; RE quality of these breweries beers... well, some are great, some are ... umm.. not. Pretty much like anything else, it's just a single step in the ladder.

Here's a probrewer.com discussion on the topic... you'll see they are pretty well split on who does/doesn't

http://probrewer.com/vbulletin/showthread.php?t=21350&highlight=rehydrate+dry+yeast

For me, I don't because a) it adds a step and I am about KISS and b) it is one more potential source for contamination.

whatever... make beer... be happy...

In the end the ONLY thing that matters is what hits the glass!

wailingguitar said:

Here's a probrewer.com discussion on the topic... you'll see they are pretty well split on who does/doesn't

http://probrewer.com/vbulletin/showthread.php?t=21350&highlight=rehydrate+dry+yeast

For me, I don't because a) it adds a step and I am about KISS and b) it is one more potential source for contamination.

whatever... make beer... be happy...

In the end the ONLY thing that matters is what hits the glass!

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Really great link, thanks! It's nice to see that home brewers aren't the only brewers debating this. I'm guessing that it'll never be settled. Those of us who hydrate will, and those who don't won't. We'll all make beer, many of us'll make great beer, and I betcha most of us wouldn't be able to tell the difference between which of those beers used rehydrated dry and which used dry pitched yeast.

Thanks for the help guys. I actually had some family things come up when I was heating up my strike water so I decided just to toss the yeast and grab a new pack when I brew this weekend or next. I didn't have time to clarify in my earlier posts but the yeast was a half pack of US-05 that was vacuum sealed about 10 days ago and put in the fridge. I was hoping it was still good to use and thought rehydrating and proofing would be a good idea. Next time i'll just rehydrate and forget about proofing. Since I do only 1g batches, it really sucks that the dry yeast doesn't last long after opening.

I like to rehydrate for two reasons.

First, I find it far easier to get the yeast nicely dissolved in my measuring cup than in my fermenter (while I don't doubt that pouring on to the yeast helps with mixing, I usually have some more cooling to do before I transfer from my kettle to the fermenter and I generally like to follow manufacturer's directions, which rather universally suggest sprinkling on top)

Second, it gives me something to do while I'm cooling the wort.

I've never bothered "proofing," and I'd say it's pretty conclusively outdated as a method. I doubt it will hurt much, but the dry yeasts I've used have all self-proofed just from rehydrating in water. The only reason I can think of that one might do that is if the yeast packet were very old or had been through serious mis-handling. However, I think I'd be more inclined to make a proper starter to test it rather than just proofing. (More likely, I'd drop the $4 for a fresh packet, since that's what, a buck or two more than the DME for a starter?)

NordeastBrewer77 said:

Really great link, thanks! It's nice to see that home brewers aren't the only brewers debating this. I'm guessing that it'll never be settled. Those of us who hydrate will, and those who don't won't. We'll all make beer, many of us'll make great beer, and I betcha most of us wouldn't be able to tell the difference between which of those beers used rehydrated dry and which used dry pitched yeast.

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Just bought some 05 for a pumpkin ale i plan on doing over the weekend. The guys at my LHBS (who i trust because they make great beer) said don't bother and just sprinkle it on top of my wort. Since it's higher gravity they did suggest getting two packs. Still cheaper than a smack pack of 1056.