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When to rehydrate dry yeast?

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mullimat

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I have been reading a lot about how the liquid yeast packs need to be set out a few hours to warm up and then i think you're supposed to activate them and let them sit for a few hours more before pitching? Maybe i have it wrong. Anyways, i'm about to brew my first time tomorrow and i will be using nottingham yeast. I know this needs to be rehydrated so when would i do that? Will it be done a few hours before i pitch it (like should i rehydrate it tonight?) or when?
 

malkore

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do it about 15 - 30 minutes before you pitch.

dry yeast is real simple. its best to boil a cup of water, then cool it with some tinfoil over the top (to keep it sanitary). when the water's 70-80F, dump in the yeast and just lightly stir it in so its all wet. then let it chill a bit.

Now, since its your first brew, remember you've got to cool the wort down to 70-75F too, and that can take a little while.

its perfectly fine to wait on the yeast until you get the wort cool. then just keep the bucket lid on, or the carboy cap/bung in place while the yeast hydrates.

Right before you pitch the yeast, stir it up a little (with a sanitized spoon) and that'll make it really easy to pour. no yeast sludge at the bottom.
 

AFAJ Brew Guy

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I usually just warm up about a cup of spring water on the stove to about 90, poor that into a sanitized measuring on top of the yeast while I am cooling my wort. Just cover with some aluminum foil. When I have everything in primary I just poor her in!

Edit: Yeah like malkore said! :)
 
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mullimat

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Cool! Thanks for the info! I can't wait to start brewing.
 

mrk305

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The directions on the packet from Nottingham say to hydrate, so who am I to argue.................

I don't think 15 minutes or an hour makes any difference. I boil my hydrating water when I start heating my mash water and I add my yeast to the glass of water sometime after the boil has started. I put all my stuff on a TV tray in order of additions so I don't forget to add anything. I have almost forgot to add the yeast a couple times. (yeah, I drink when I brew)
 

Blender

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I don't think it hurts at all so I wait until the wort is at pitching temp and they rehydrate with preboiled water. I see activity in 20-30 minutes.
 

Professor Frink

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I've done both rehydrating and non-rehydrating. I've noticed the yeast take off quicker when rehydrated, and it takes almost no effort.
 

MikeFlynn74

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Ahh So I was wrong- Ive never rehydrated and never had an issue. But I might try it next time.
 

Bobby_M

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It's not absolutely necessary and you could probably pitch dry forever and never see any big difference. I just like to start with as much yeast as possible so that they get a hold of the wort before any potential undesirables do. Pitching dry kills something like half of the available cells right away.
 

HP_Lovecraft

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The "high end" SafAle directions simply state "pour dry yeast over aerated wort".

It is an old debate. My shortest lag ever was with a package of SafAle S-04, pitched dry. Airlock moving in just 4 hours. Done within 30 hours.

For a beginner, pitching dry reducing chances of infection, as well as chances of killing the yeast from inpatience. As the beginner gets better with sanitation, and temp control, then rehydration does offer minimal improvement, expecially for more complex beers (higher OG, lagers, etc).

nick
 

malkore

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HP_Lovecraft said:
The "high end" SafAle directions simply state "pour dry yeast over aerated wort"

nick

Not true...look at their website:
http://www.fermentis.com/FO/EN/06-Ales/100-10_directions_cb.asp

"The yeast can be re-hydrated into a cream prior to pitching or added dry, direct to the fermenting vessel. The goal is to maintain the viability of as many yeast cell as possible. From work done in our laboratories, viability can be enhanced by elevating the temperature of the rehydration stage above the desired fermentation starting temperature (23C ± 3C for Saflager and 27 ± 3C for Safbrew and Safale) for a short period. Full details are available on the PDF download for each yeast strain."

Full details from http://www.fermentis.com/FO/EN/pdf/SafaleS-04.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. 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. 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."

they just can't fit all that info on a tiny 2"x2" foil packet. I always make a cream out of my Fermentis yeast. its simply easier to pitch (no yeast sludge at the bottom)
 

Bobby_M

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HP_Lovecraft said:
The "high end" SafAle directions simply state "pour dry yeast over aerated wort".

It is an old debate. My shortest lag ever was with a package of SafAle S-04, pitched dry. Airlock moving in just 4 hours. Done within 30 hours.

For a beginner, pitching dry reducing chances of infection, as well as chances of killing the yeast from inpatience. As the beginner gets better with sanitation, and temp control, then rehydration does offer minimal improvement, expecially for more complex beers (higher OG, lagers, etc).

nick
Pitching dry kills yeast (which to me is an act of impatience). Please try to explain why my rehydrated samples showed a shorter lag compared to the non-rehydrated samples in this split batch experiment. What other variable could be contributing if not the rehydration?

[YOUTUBE]vOrfmzpDmPk[/YOUTUBE]
 

Danek

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Speaking personally, I'd always rehydrate my dry yeast. But "rehydrating dry yeast or not" is one of those decisions that is almost certainly never going to make a difference between good and bad beer. I think rehydrating would be best practice, but if you wanted to keep the process simple, I don't think there'd be any problems pitching dry.
 

HP_Lovecraft

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malkore said:
Not true...look at their website...
I know, I was just stating that THE PACKAGE states to use the dry pitch method.

As you said, the reason is most likely that they were simply limited by space, and had to use the simpliest instructions. But on the other-hand, the most highly regarded dry-yeast maker uses the dry-pitch instructions on the package. That still says something.

Pitching dry kills yeast
I agree 100%. I was referring to the first time I rehydrated 8 years ago. The water had not cooled down below 100 degrees yet, and all the yeast died as a result. Impatience to blame.

Certaintly proper rehydration reduces lag by increasing viable cells, and decreasing acclimation time. But by design, dry yeast packets have an extremely high yeast count to begin with.

nick
 
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