Rehydrate Safale US05 YEs or NO?

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JoseLima

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I making an American IPA and OG is going to be 1.065-1.070 and I am going to use Safale US 05.. Should I just rehydrate 1 packet or just pitch 2 packets or should I rehydrate 2 packets?
 
One packet will be fine at that OG, and I agree that rehydrating is easy, especially if you just use a microwave to boil the water in a pyrex measuring cup, cool it in a small water bath, and add the yeast to the water at 95*-105*.
 
According to Brewing Classic Styles 5.5G of 1.070 SG wort needs about 275B yeast cells. According to the same book you will get 10-20B cells per gram of dry yeast.

Fermentis spec sheet for US-05 (don't know which yeast you are actually using) says there are 6B viable yeast cells per gram.

So to decide how much yeast to use decide how many viable yeast cells per gram you think you will get and divide 275 by that number. There are 11 grams per pack.

I would assume somewhere in the middle and go with 2 packs.
 
I know this is against the grain here, but I pitch dry yeast directly into the wort and I've never had a single problem. US-05 usually takes off for me within 24 hours from dry. I know its easy to do and I know there is some benefit to it, but from my experience, I end up with great fermentations and I don't feel the need to change it up.
 
I know this is against the grain here, but I pitch dry yeast directly into the wort and I've never had a single problem. US-05 usually takes off for me within 24 hours from dry. I know its easy to do and I know there is some benefit to it, but from my experience, I end up with great fermentations and I don't feel the need to change it up.

To beat a dead horse...zactly. One packet will do, but I'd probably put in two for sh&^ and giggles.
 
I'd go 2 packets, rehydrated. Why skimp on yeast, you don't cut corners anywhere else, do you?
 
I know this is against the grain here, but I pitch dry yeast directly into the wort and I've never had a single problem. US-05 usually takes off for me within 24 hours from dry. I know its easy to do and I know there is some benefit to it, but from my experience, I end up with great fermentations and I don't feel the need to change it up.

I've done both and have not seen any difference. Save yourself some time and pitch it dry on some well aerated wort.
 
I've done both and have not seen any difference. Save yourself some time and pitch it dry on some well aerated wort.

^^^ This. Experimented with dry vs rehydrating on a commercial scale and came to the conclusion that there was no appreciable difference. Since it is a) an extra step and, therefore, b) another potential source of contamination, I simply don't bother with rehydrating.

It is true that a large number of cells won't survive the pitch, BUT the ones that do survive feast on the weak... so to speak. I pitch 1 pack into 5 gallons and typically see signs of fermentation in around 8 hours. No problems.

Also, dry yeast includes sufficient lipids for growth so that aeration is not actually necessary... I aerate anyway, but don't get extreme.. just let the wort splash and churn as I pour it into my ferm...
 
Seems I've been seeing people suggesting rehydrating dry yeast here and there lately. I just started brewing a few years ago, but everyone I talked to always said to pitch it dry. I know to rehydrate for bread baking, but that's basically to make sure it's alive and healthy. With beer yeast, you can check the date on the package and avoid anything too old. Generally those packets are designed for 5 gallon batches, right? The OP didn't specify batch size, but I think we're all assuming the 5 gallon range. I've never needed more than one packet, dry. If all you can find is some yeast with a little age on it, you could pitch two. Or, if you're adventurous and get some equipment, you could rehydrate one packet and make a starter!
 
I always rehydrate as it just seems to take off faster and ferment faster. I use an O2 wand to aerate which is key especially if you drop it dry but I made a blonde yesterday and was out of pure 02 so I rehydrated 05 which is a notoriously slow starter and fermentation has kicked off I n less than 24 hrs. Not sure if that's from rehydrating or not but I'll always do it. Jmo
 
I have always been surprised to look at some of the dry yeast packets and see directions to just sprinkle it on the wort. Then if you go digging on the lab's website or look for videos you will find advice from them to rehydrate the yeast.

Many say that sprinkling the yeast on the wort will kill as much as half of the cells. Does anyone have a link to a study proving this?
 
iirc, Chris White in Yeast covered this.

The pdfs on the Fermentis web site recommend hydration before simply sprinkling.
Between that and the reported high mortality incurred by sprinkling, I've always hydrated - I don't even have a "sprinkling baseline" to compare against...

Cheers!
 
I have always been surprised to look at some of the dry yeast packets and see directions to just sprinkle it on the wort. Then if you go digging on the lab's website or look for videos you will find advice from them to rehydrate the yeast.

Many say that sprinkling the yeast on the wort will kill as much as half of the cells. Does anyone have a link to a study proving this?

http://seanterrill.com/2011/04/01/dry-yeast-viability/

http://seanterrill.com/2011/07/29/dry-yeast-viability-take-two/

This kind of supports @masskrug though

http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/
 
Always re-hydrate.

Yes you will make beer even if you don't. But please don't come here complaining of off flavors or slow fermentation starts.
 
I'm not saying it's wrong, but why is it that I'm hearing this NOW, and not 3 years ago? And when I was getting started, I talked to a BUNCH of experienced and reputable brewers, including a few beer geniuses and NOBODY said I should rehydrate dry yeast. I've heard that I need to aerate...which I do. I know temperature is important...I'm actually FINALLY able to address that. Most of my beers that didn't have the temp control, but didn't really require it, turned out pretty good; but my US-05 stout and porter attempts, while they took off pretty quickly, I was not too impressed with the flavors and they eventually overcarbed (I bottle, no kegging). Since I got a fermentation chamber set-up finally, I'm doing another stout...but NOT using US-05, because I thought the yeast might be my issue (in addition to the temps). I used Wyeast 1968 smackpack for the current brew...and it took awhile to show signs of life at 64F, but samples have been delicious. If I give US-05 a try again, I'll try rehydrating...could be that was the problem rather than the temperature...or a combination of the two.
 
Anecdotally, I rehydrated a Nottingham Thurs, pitched it in a 1.050 wort and saw action within four hours. I have pitched without rehydrating and did not see action so quickly. YMMV
 
Anecdotally, I rehydrated a Nottingham Thurs, pitched it in a 1.050 wort and saw action within four hours. I have pitched without rehydrating and did not see action so quickly. YMMV

I guess I just have to be different.

The last six or so brews I have done with US-05 I did a yeast starter. Never had to wait more than four hours for fermentation activity. Within 24 hours the activity in the fermenter has been mind boggling.

The only faster full ferment I ever had was when I made the mistake of using an entire US-05 yeast cake for an IPA. Thank heavens for headspace! That thing took off like a rocket.
 
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