05 rehydrate or not?

Fermentis recommends rehydrating the dry US-05 yeast for the best performance. If you pitch dry, half of the yeast will die, per Dr. Cone. I am too cheap to waste half the yeast or risk my sweet wort.

“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.”

http://www.fermentis.com/fo/60-Beer/60- ... angeHB.asp

Flying in the face of science and recommendations, I’ll keep using it without rehydrating until I find I have a problem doing that. After several dozen uses of 05 without rehydrating, that problem hasn’t happened.

Where did you get the information about this loss by pitching yeast without rehydration? Just curious.

I vary in what I do, depending on my time available. I’m not convinced there is a wrong way to do it.

I rehydrated a few packs with my stirplate awhile back.
Probably the easiest thing in the world of brewing to do.
After you pour your first cup of coffee in the morning, put 1 cup of water in your flask, cover with foil, put on stove.
In like 2 minutes its boiling WFO. Kill heat.
Even the guys that can knock out a brew day in 2 hours will have a flask of cooled ~100* sterile water by the time their wort is cooling.
But I did’nt like how 05 wouldnt take off like a stepped starter of 1056, especially at less than recommended temp range.
Then I guess I stopped liking either one because their pretty boring.
So I may have had alot of cells, but they were lazy ass cells IMO that would’nt do anything until I got the temp above 55*

Where did you get the information about this loss by pitching yeast without rehydration? Just curious.

I vary in what I do, depending on my time available. I’m not convinced there is a wrong way to do it.[/quote]
Found it.http://koehlerbeer.com/2008/06/07/rehyd … yton-cone/
DO NOT READ IF YEAST DEATH MAKES YOU SAD
Dr Clayton says:
I appreciate your dilemma It is a universal problem for those that market
Active Dry Yeast.

Let me give you some facts regarding rehydration and you can decide for
yourself where you want to compromise.
Every strain of yeast has its own optimum rehydration temperature. All of
them range between 95 F to 105F. Most of them closer to 105F. The dried
yeast cell wall is fragile and it is the first few minutes (possibly
seconds) of rehydration that the warm temperature is critical while it is
reconstituting its cell wall structure.

As you drop the initial temperature of the water from 95 to 85 or 75 or 65F
the yeast leached out more and more of its insides damaging the each cell.
The yeast viability also drops proportionally. At 95 – 105 F, there is
100% recovery of the viable dry yeast. At 60F, there can be as much as 60%
dead cells.

The water should be tap water with the normal amount of hardness present.
The hardness is essential for good recovery. 250 -500 ppm hardness is
ideal. This means that deionized or distilled water should not be used.
Ideally, the warm rehydration water should contain about 0.5 – 1.0% yeast
extract

For the initial few minutes (perhaps seconds) of rehydration, the yeast
cell wall cannot differentiate what passes through the wall. Toxic
materials like sprays, hops, SO2 and sugars in high levels, that the yeast
normally can selectively keep from passing through its cell wall rush right
in and seriously damage the cells. The moment that the cell wall is
properly reconstituted, the yeast can then regulate what goes in and out of
the cell. That is why we hesitate to recommend rehydration in wort or
must. Very dilute wort seems to be OK.

We recommend that the rehydrated yeast be added to the wort within 30
minutes. We have built into each cell a large amount of glycogen and
trehalose that give the yeast a burst of energy to kick off the growth
cycle when it is in the wort. It is quickly used up if the yeast is
rehydrated for more than 30 minutes. There is no damage done here if it is
not immediatly add to the wort. You just do not get the added benefit of
that sudden burst of energy. We also recommend that you attemperate the
rehydrated yeast to with in 15F of the wort before adding to the wort.
Warm yeast into a cold wort will cause many of the yeast to produce petite
mutants that will never grow or ferment properly and will cause them to
produce H2S. The attemperation can take place over a very brief period by
adding, in encrements, a small amount of the cooler wort to the rehydrated
yeast.

Many times we find that warm water is added to a very cold container that
drops the rehydrating water below the desired temperature.

Sometimes refrigerated, very cold, dry yeast is added directly to the warm
water with out giving it time to come to room temperature. The initial
water intering the cell is then cool.

How do many beer and wine makers have successful fermentations when they
ignore all the above? I believe that it is just a numbers game. Each gram
of Active Dry Yeast contains about 20 billion live yeast cells. If you
slightly damage the cells, they have a remarkable ability to recover in the
rich wort. If you kill 60% of the cell you still have 8 billion cells per
gram that can go on to do the job at a slower rate.

The manufacturer of Active Dry Beer Yeast would be remiss if they offered
rehydration instructions that were less than the very best that their data
indicated.

One very important factor that the distributor and beer maker should keep
in mind is that Active Dry Yeast is dormant or inactive and not inert, so
keep refrigerated at all times. Do not store in a tin roofed warehouse
that becomes an oven or on a window sill that gets equally hot.

Active Dry Yeast looses about 20% of its activity in a year when it is
stored at 75 F and only 4% when refrigerated.

The above overview of rehydration should tell you that there is a very best
way to rehydrate. It should also tell you where you are safe in adapting
the rehydration procedure to fit your clients.

Clayton Cone.

the info above ^ is interesting. but i have a hard time understanding why water is better for yeast, rather than sugar water (ie: wort). would it be better to take out a portion of wort at 95-105F while chilling, then add it back after chilled and in carboy (that seems easy/reasonable and by the time the wort has cooled, the rehydration wort will have been cooling to room temp)

here is my 2 cents.

cent #1: i respect denny as a brewer, and his experience far exceeds my own. so i usually listen to him

cent #2: i did a side by side experiment with rehydrated vs non-rehydrated and the NON rehydrated started fermentation quicker. it was my first 10 gallon batch, two 5 gallon fermenters in the SAME swamp cooler. not only did it start fermenting sooner, but (i thought) it turned out slightly better. (IMO, (and my opinion is always biased)) (lag time could be attributed to a cold package immediately introduced to warm water, but i don’t remember)

this is a very heated topic in the homebrewing community. i’ve read several pages with nothing but arguments on the subject. the best answer is: whatever works for you - works.

Dr. Cone is one of the leading yeast researchers in the world. He was also in charge of the Lallemand dry yeast production. I’ll take his word for it.
:cheers:

[quote=“TG”]Dr. Cone is one of the leading yeast researchers in the world. He was also in charge of the Lallemand dry yeast production. I’ll take his word for it.
:cheers: [/quote]

Tom, there’s no way I can take his word for it when my own experience directly contradicts what he says. I believe that in theory he’s correct, but like many things in homebrewing, practice differs from theory.

Let’s do a triangle test!

:smiley:

You know I have great respect for your talents and opinions. And maybe I just can’t tell the difference. But I have never had any problems due to not rehydrating dry yeast and can’t tell any difference in the beer when I do it. Being the pragmatic type, I have to go with my own experience. I encourage everyone to do the same.

ETA: tell ya what…the next time I use dry yeast I will do the “TG Memorial Rehydration” in your honor! I’ll let ya know what the results are.

I have a hard time understanding why water is better for yeast, rather than sugar water (ie: wort). would it not be better to take out a portion of wort at 95-105F (to rehydrate with) while chilling, then add it back after chilled and in carboy?

sorry to ask twice, but i’m curious. anyone try this?

i never rehydrated my dry yeast for the first 3 brews and i found this post yesterday, well without rehydrating fermentation began within 12 hours. last night i brewed the midnight beatdown partial mash and decided to try rehydrating the us 05 to see the difference. boiled about 4-6 ounces of water, let it cool to 78 degrees in a sterile flask i added the yeast. put it on my stir plate i just made at low speed. cuz of the instructions on fermentis’ website : “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.” left in on the plate for about an hour. then pitched into my wort at 66 degrees. well its been 12 hours and no signs of fermentation. i dont know if i should be worried yet, but i am. im used to seeing active fermentation the next morning, and there is nothing after 13 hours now. im sold on not rehydrating now, i should have trusted my instincts, i just wanted to use my new stir plate, whoops. at what point should i re pitch a dry pack of us 05? after 24 hours of no signs of activity? 48? temp of wort is stable at 66. thanks for any advice.

:smiley:

You know I have great respect for your talents and opinions. And maybe I just can’t tell the difference. But I have never had any problems due to not rehydrating dry yeast and can’t tell any difference in the beer when I do it. Being the pragmatic type, I have to go with my own experience. I encourage everyone to do the same.

ETA: tell ya what…the next time I use dry yeast I will do the “TG Memorial Rehydration” in your honor! I’ll let ya know what the results are.[/quote]
I hardly make the same beer twice, so I don’t know that I would have even had the chance to compare. I’ll try to do one and have our homebrew club do a triangle test with them.
:cheers:

[quote=“S.Scoggin”]I have a hard time understanding why water is better for yeast, rather than sugar water (ie: wort). would it not be better to take out a portion of wort at 95-105F (to rehydrate with) while chilling, then add it back after chilled and in carboy?

sorry to ask twice, but i’m curious. anyone try this?[/quote]

The explanation I’ve heard is that sugar increases the gravity of the water, which in turn increases the osmotic pressure on the yeast cells and can cause them to burst. Of course, that’s also an argument to not sprinkle the yeast directly on the wort, which is what I do…

I’d give it 36-48 hours. If nothing by then, repitch.

thank you sir. :cheers:

[quote=“TG”]I hardly make the same beer twice, so I don’t know that I would have even had the chance to compare. I’ll try to do one and have our homebrew club do a triangle test with them.
:cheers: [/quote]

Cool! If you do it, be sure to report back!

Okay guys, first attempt at rehydrating into 6 oz of sterile water there was not activity in carboy within about 18-20 hours. For some reason I woke up in the middle of the night to check, and it was bubbling away more vigorously than what I’ve seen with smack packs i’ve used (all of which were 1056).

I did notice before active ferm started there were 5 or 6 clusters of white particles on top of the wort…possibly clusters of yeasties waiting to get it on??? As of now its all good and motor boating away!!
OG of 2.5 gal of wort is 1.067.

my midnight beatdown with rehydrated us o5 from last week started fermenting at about 24 to 36 hours after pitching. started slow then got to what im used to seeing pitching dry. overall fermentation was slower to start, slower to end, and ended up with a relatively high FG, 1.018, but this was my first PM and i mashed a little high. followed the directions with the kit again(should have learned from previous batches) my mash temp was about 160 lowering to about 154 after the hour. so i blame myself for the high FG, not the rehydrated yeast. i also added yeast nutrient for the first time. from the sample at testing im happy with the flavor, not too sweet, not chewy, not dry. i think it will be the best yet. also plan to dry hop this with an ounce of cascade pellets when i rack to secondary in a couple days. never done that before either, hope it will turn out good.

i also rehydrated us o5 again this week when i brewed a rye ale. same lag time about 24- 36 hours. slow start, strong finish. krausen just dropped after 5 days.

I brew pretty much exclusively with S05. For a couple years I didnt rehydrate but decided to start doing so last year. Trouble is I found Ive been doing it too cold. I bought a book called “Yeast” by Chris White and Jamil and it fully covers with detail the why and the how of rehydrating. I bought a product called Go-ferm from Lallemand that is made expressly for adding nutrients ( not sugars) to rehydration water. I plan to follow the proper rehdration protocals and use Go-ferm next brew session and therafter this year and look for improvements in the finished beer.
Personally Ive not liked any of my beers where Ive pitched two packets dry straight into the wort. My best beers thus far have been rehydrated according to the instructions from Fermentis. I think the Go-ferm will be most helpful when I brew with 34/70 Lager this spring but I want to check the stuff out with S05 first.