Author Topic: yeast starter from dry yeast  (Read 1549 times)

Offline homoeccentricus

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yeast starter from dry yeast
« on: February 24, 2016, 04:43:37 PM »
Is it really true that one should not make a yeast starter from dry yeast, because you exhaust the yeast and blablabla or is this just one of those bullsh*t stories?
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Offline stpug

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Re: yeast starter from dry yeast
« Reply #1 on: February 24, 2016, 04:49:50 PM »
That's how the story goes.

First time I used dry yeast I did a starter (because I didn't know any better). As expected, everything turned out wonderfully.  :D (probably just wasted effort on my part)

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Re: yeast starter from dry yeast
« Reply #2 on: February 24, 2016, 04:52:17 PM »
Is it really true that one should not make a yeast starter from dry yeast, because you exhaust the yeast and blablabla or is this just one of those bullsh*t stories?

Yes, that's all true IMO.  But to me, the I bigger reason is that you don't need to.
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Offline dmtaylor

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Re: yeast starter from dry yeast
« Reply #3 on: February 24, 2016, 04:56:17 PM »
The one time when I would advise it is for krausening to get rid of diacetyl or the finishing gravity being too high.  Sprinkling dry yeast on either of those would likely be fruitless.  But for initial pitch, you never need a starter for that with dry yeast.  It's the big advantage.
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Offline homoeccentricus

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Re: yeast starter from dry yeast
« Reply #4 on: February 24, 2016, 05:00:38 PM »
I know you don't have to. I don't even use dry yeast a lot. I just want to know that if you make a starter from dry yeast, you weaken it considerably... Obviously the proof would require an experiment that I'm not willing to do personally ;)
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Re: yeast starter from dry yeast
« Reply #5 on: February 24, 2016, 05:04:54 PM »
The one time when I would advise it is for krausening to get rid of diacetyl or the finishing gravity being too high.  Sprinkling dry yeast on either of those would likely be fruitless.  But for initial pitch, you never need a starter for that with dry yeast.  It's the big advantage.

For krausening, you need to add actively fermenting wort, not just yeast.
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Offline dmtaylor

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Re: yeast starter from dry yeast
« Reply #6 on: February 24, 2016, 06:11:32 PM »
Well yes of course.
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Re: yeast starter from dry yeast
« Reply #7 on: February 24, 2016, 06:12:44 PM »
Well yes of course.

After I typed that, I realized that's what would be happening.
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Offline stpug

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Re: yeast starter from dry yeast
« Reply #8 on: February 24, 2016, 07:00:09 PM »
I know you don't have to. I don't even use dry yeast a lot. I just want to know that if you make a starter from dry yeast, you weaken it considerably... Obviously the proof would require an experiment that I'm not willing to do personally ;)

I would not equate "making a starter with dry yeast" to "weakening it considerably".  It's just not necessary for most 5 gallon batches; now if you were aiming for a 10 gallon batch of significant gravity and only had 1 sachet of dry yeast on hand then a starter should help in this regard.

Offline narcout

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Re: yeast starter from dry yeast
« Reply #9 on: February 24, 2016, 07:00:52 PM »
I just want to know that if you make a starter from dry yeast, you weaken it considerably... Obviously the proof would require an experiment that I'm not willing to do personally ;)

The nice thing about dry yeast is that (paraphrasing from S. Cerevisiae and the Lallemand website) it is propagated in a manner that results in high levels of ergosterol and UFA reserves.  As such, you do not really need to aerate/oxygenate your wort on an initial pitch.  The other nice thing is that there are a lot of cells in each packet.

I think making a starter with dry yeast is less about weakening the yeast and more about just not being necessary, since you already have a good amount of fully charged cells.
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Offline Hickory

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Re: yeast starter from dry yeast
« Reply #10 on: February 24, 2016, 07:04:28 PM »
What about making a big starter from dry yeast and only pitching half, and keep the rest for a future brew day, say a week or two later?

Offline hopfenundmalz

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Re: yeast starter from dry yeast
« Reply #11 on: February 24, 2016, 10:13:12 PM »
I know you don't have to. I don't even use dry yeast a lot. I just want to know that if you make a starter from dry yeast, you weaken it considerably... Obviously the proof would require an experiment that I'm not willing to do personally ;)

I would not equate "making a starter with dry yeast" to "weakening it considerably".  It's just not necessary for most 5 gallon batches; now if you were aiming for a 10 gallon batch of significant gravity and only had 1 sachet of dry yeast on hand then a starter should help in this regard.
Make a five gallon starter, say a 1.050 OG beer. Use the yeast cake for 10 gallons of the big beer. Aerate the big beer, and add nutrients.mthis has worked for me.
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Offline crakers540

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Re: yeast starter from dry yeast
« Reply #12 on: February 25, 2016, 12:44:34 AM »
ok, please help me understand.  I have always been a fan of creating a starter culture to pitch into my beers, whether I use a liquid or dry yeast to start with.  I use 500mls of wort, and pitch the dry or active liquid yeast (bulging packet) into it, a few days before brewing, hoping to allow it to reach the maximum logarithmic stage of growth to pitch into my 5 gallons of wort.

My thinking is that the entire 500mls will be filled with loads of yeast in their most prolific phase of growth, and the starter culture will contain tons of enzymes from the yeast ready to continue to cleave sugars into yeast food, so that I get a vigorous, almost violent, start to my fermentation so as to help avoid contamination, get a good start, etc.

Maybe it is just me, but I feel better when I Pitch a starter that is showing good signs of growth into my just-made wort.

Again, please help me understand if I am just wasting my time preparing a starter culture.  I have never pitched only dry yeast into my just-made wort.

Offline narcout

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Re: yeast starter from dry yeast
« Reply #13 on: February 25, 2016, 01:41:42 AM »
In theory, there isn’t much point in making a starter with dry yeast for the reasons explained above: you already have a large cell count of yeast with healthy UFA and ergosterol reserves that require little or no additional oxygen on the initial pitch.

With liquid yeast, you are generally starting with a lower cell count and the cells do not have the same levels of UFA and ergosterol due to the method of propagation.  You can increase the amount of cells you are pitching by using a starter (though I don’t think you are going to see much growth pitching a full smack pack into a half liter starter). 

For some interesting information on growth, check out this blog post: http://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons

See also reply #56 in the following thread: https://www.homebrewersassociation.org/forum/index.php?topic=24460.msg312443#msg312443

Then you have the choice of pitching the starter at high krausen (when UFA and ergosterol reserves are supposedly higher) or waiting until the starter ferments out, decanting, and pitching just the slurry (when reserves are supposedly lower). 

There has been a ton of discussion on these topics here recently, though perhaps not much consensus.  A good chunk of it was posted by user S. Cerevisiae.  If you search this forum for his posts using key words like “ergosterol,” “maximum cell density,” or "morphological changes" you will find a lot of information.

As an example, see reply #48 in the following: https://www.homebrewersassociation.org/forum/index.php?topic=24041.msg306967#msg306967

See also reply #5 in this thread: https://www.homebrewersassociation.org/forum/index.php?topic=25207.msg323689#msg323689

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Offline crakers540

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Re: yeast starter from dry yeast
« Reply #14 on: February 25, 2016, 02:53:04 AM »
In theory, there isn’t much point in making a starter with dry yeast for the reasons explained above: you already have a large cell count of yeast with healthy UFA and ergosterol reserves that require little or no additional oxygen on the initial pitch.

With liquid yeast, you are generally starting with a lower cell count and the cells do not have the same levels of UFA and ergosterol due to the method of propagation.  You can increase the amount of cells you are pitching by using a starter (though I don’t think you are going to see much growth pitching a full smack pack into a half liter starter). 

For some interesting information on growth, check out this blog post: http://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons

See also reply #56 in the following thread: https://www.homebrewersassociation.org/forum/index.php?topic=24460.msg312443#msg312443

Then you have the choice of pitching the starter at high krausen (when UFA and ergosterol reserves are supposedly higher) or waiting until the starter ferments out, decanting, and pitching just the slurry (when reserves are supposedly lower). 

There has been a ton of discussion on these topics here recently, though perhaps not much consensus.  A good chunk of it was posted by user S. Cerevisiae.  If you search this forum for his posts using key words like “ergosterol,” “maximum cell density,” or "morphological changes" you will find a lot of information.

As an example, see reply #48 in the following: https://www.homebrewersassociation.org/forum/index.php?topic=24041.msg306967#msg306967

See also reply #5 in this thread: https://www.homebrewersassociation.org/forum/index.php?topic=25207.msg323689#msg323689

Thanks for the reply, good information and articles.  Helps me understand better the where I need to be with my pitching yeast.