Author Topic: Pitching dry yeast without rehydrating  (Read 5817 times)

Offline denny

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Re: Pitching dry yeast without rehydrating
« Reply #30 on: May 25, 2012, 01:27:09 PM »
The whole point of using dry yeast for me is convenience. While boiling some water and letting it cool isn't has much work as making a starter, it's still an added step I'm not going to mess with. I do agree that rehydrating the dry yeast makes it look prettier going in the fermenter. Maybe that's what people like so much, the aesthetics.    ;)

If I had proven to myself that it made better beer, I'd be more than willing to do it.
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Offline ynotbrusum

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Re: Pitching dry yeast without rehydrating
« Reply #31 on: May 25, 2012, 01:35:38 PM »
Of course repitching from dry yeast cakes is another matter...
Hodge Garage Brewing: "Brew with a glad heart!"

Offline corkybstewart

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Re: Pitching dry yeast without rehydrating
« Reply #32 on: May 25, 2012, 02:56:46 PM »
Read this article:  It's long and old, but solid info.

This is great info everybody using dry yeast should read:
Dr Clayton Cone the Yeast Guru from Lallemand had an interesting discussion with Dan Litermann on the Homebrewers Digest ( hbd.org ) about rehydrating BACK IN 2000 .

.
Subject: Yeast Q's- Dan Listerman- Dr. Cone
Date: 2000-04-14 20:56:55 GMT
From: Dan Listermann <72723.1707@compuserve.com>
Subject: Yeast Hydration, Infusion Mashing and England

My question to Dr. Cone regards yeast rehydration. All the packages of
yeast contain instructions for rehydration yet they all ferment just fine
without it. I have to believe that such a procedure may be theoretically
beneficial, however it would seem to be margionally usefull at least on a
homebrew scale.

I own a home brew shop and a very common phone call is the " My beer is not
fermenting." problem. I go through the list of potential causes ( plastic
bucket lid leaks, too cold, ect.) About twice a week the caller will
indicate that he rehydreated the yeast. This is a strong signal that the
yeast has been damaged and will need to be replaced. I have come to the
conclusion that, since rehydration is not necessary to ferment beer
properly and there is a strong chance that the yeast will be damaged in a
botched rehydration, it is not desirable to recommend such a proceedure.
Just how important is rehydration and is it worth the risk?

Dan Listermann dan@listermann.com 72723.1707@compuserve.com

Dan,
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.

--
I'd really just rather be brewing in sunny Carlsbad New Mexico

Offline tom

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Re: Pitching dry yeast without rehydrating
« Reply #33 on: May 27, 2012, 08:00:36 AM »
Do what you want but I always rehydrate my dry yeast. It just doesn't make sense to do all that work- carefully measuring and sanitizing etc and then cavalierly toss the dry yeast in. It seems that dry yeast is considered to be so substandard that any extra effort is deemed worthless.

Well, I hydrate even on lower gravity beers. It works well for me and suggest that you use plain boiled and cooled tap water to do so. Hydrate at 85-90F. Never use RO or distilled to hydrate the yeast.

Good luck.
+1, it's easy to pour 4 oz of boiling water into a pyrex measuring cup and sprinkle the yeast on.  Otherwise you are just throwing away half of your yeast.
Brew on

Online jeffy

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Re: Pitching dry yeast without rehydrating
« Reply #34 on: May 27, 2012, 10:21:01 AM »
Do what you want but I always rehydrate my dry yeast. It just doesn't make sense to do all that work- carefully measuring and sanitizing etc and then cavalierly toss the dry yeast in. It seems that dry yeast is considered to be so substandard that any extra effort is deemed worthless.

Well, I hydrate even on lower gravity beers. It works well for me and suggest that you use plain boiled and cooled tap water to do so. Hydrate at 85-90F. Never use RO or distilled to hydrate the yeast.

Good luck.
+1, it's easy to pour 4 oz of boiling water into a pyrex measuring cup Let it cooland sprinkle the yeast on.  Otherwise you are just throwing away half of your yeast.
I thought I would add that, otherwise you are just throwing away all of your yeast.
Jeff Gladish, Tampa (989.3, 175.1 Apparent Rennarian)
Homebrewing since 1990
AHA member since 1991, now a lifetime member
BJCP judge since 1995

Offline liquidbrewing

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Re: Pitching dry yeast without rehydrating
« Reply #35 on: May 28, 2012, 04:10:44 PM »
So, I'm trying to draw Mr. Denny Conn out here.  Have you noticed any thing different (off flavors, etc...) just pitching the dry yeast pack without rehydrating?  Anything over 1.060 I just pitch two packs, but is the rumor true that if you pitch dry yeast, without rehydrating,  it kills half the cells instantly?  This doesn't really make any sense to me, as I usually rehydrate in around 85 degree water.  Wouldn't that kill some cells too?  Why does it make a difference when you pitch into wort, is it because of the sugar content, like it's such a shock to the yeast?  Just need a little food for thought.


Warm water is better for them. Follow the recommendations from the yeast manufacturer and I think you'll be happiest with results.

My US-05 pack says, "Sprinkle into wort".  Would be hard to sprinkle water into a carboy I think... 8)  And that's what I did, sprinkle dry that is.
Justin
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Offline ccfoo242

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Re: Pitching dry yeast without rehydrating
« Reply #36 on: May 28, 2012, 05:27:10 PM »
My US-05 pack says, "Sprinkle into wort".  Would be hard to sprinkle water into a carboy I think... 8)  And that's what I did, sprinkle dry that is.

White Labs and Wyeast liquid yeasts say to dump into the carboy also, but most people make starters to get a better cell count. Both liquid and dry yeasts are easy enough to use but better results can come from better techniques.

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Offline Al Equihua

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Re: Pitching dry yeast without rehydrating
« Reply #37 on: May 29, 2012, 09:37:25 AM »
interesting thread,...now i know better
Al Equihua

Offline kgs

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Re: Pitching dry yeast without rehydrating
« Reply #38 on: May 30, 2012, 06:02:08 AM »
My US-05 pack says, "Sprinkle into wort".  Would be hard to sprinkle water into a carboy I think... 8)  And that's what I did, sprinkle dry that is.

White Labs and Wyeast liquid yeasts say to dump into the carboy also, but most people make starters to get a better cell count. Both liquid and dry yeasts are easy enough to use but better results can come from better techniques.

Just checked my "emergency yeast" in the fridge: Lallemand packets say to "rehydrate before use" and include an illustration. I had been sprinkling but I think I will go back to rehydrating. (I use Nottingham very rarely, not sure why I picked that as emergency yeast.) Lallemand's online instructions are even more elaborate ("attemperate at steps in 5-minute intervals") but I will at least avoid the production of "petite mutants," who might climb out of the carboy at night and wreak havoc in my home.
K.G. Schneider
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