Big, big starter

[King of Cascade]

So chilling and decanting aren't causing any die-off of yeast. That's good.

And you remember reading that about 50% of the yeast die in 2 days after fermentation is finiished? I would like to see that article. I'm really interested. That is something I certainly haven't seen before.

I will try to find it this weekend and post the article. Also, Greg Dross (I think that’s his name) from Wyeast talked about it briefly at NHC

 

[babalu87]

50% die through cold crashing

Not sure if I didn't state this clear or if you're having trouble understanding it but this is what I said
Also the majority of the yeast don’t die from cold conditioning (see big mac analogy) it dies when the food runs out.

The starter will not oxidize your beer if the yeast is in the aerobic state...you know because its absorbing oxygen.

Agree, big lagers are harder but I usually make a 2000 ml starter then pitch it into 2.5 gallons of beer then make 2.5 gallons more the next day. Sure that is a lot of work but the results are worth it.

50%...........................
50% of yeast die when the food runs out?
Exactly how long does that take?
Do they die as soon as the food runs out or do they slowly starve to death?
You realize that yeast are making more yeast correct?

You're pitching 2000ml of starter into 2.5 gallons of beer and then putting 2.5 gallons on top of that the next day?

So 10% of your beer is spent starter wort............ and you're telling me the results are worth it?

 

[King of Cascade]

50%...........................
50% of yeast die when the food runs out?
Exactly how long does that take?
Do they die as soon as the food runs out or do they slowly starve to death?
You realize that yeast are making more yeast correct?

You're pitching 2000ml of starter into 2.5 gallons of beer and then putting 2.5 gallons on top of that the next day?

So 10% of your beer is spent starter wort............ and you're telling me the results are worth it?

Are you asking a serious question or are you being combative?
If you’re asking a serious question then I will try to help you out if you’re trying to be a jerk then please stop quoting me.

It starts happening as soon as the food runs out. And no not all at once.

Yes yeast grow and multiply in the lag and a few hours into the log phases….not much after that.

Yeah about 80% steep up each steep from a single colony. Would just like to point out that if you pitch a barleywine on a yeast cake from a well made 70/- then that would technically be spent starter wort…right?

 

[babalu87]

Are you asking a serious question or are you being combative?
If you’re asking a serious question then I will try to help you out if you’re trying to be a jerk then please stop quoting me.

It starts happening as soon as the food runs out. And no not all at once.

Yes yeast grow and multiply in the lag and a few hours into the log phases….not much after that.

Yeah about 80% steep up each steep from a single colony. Would just like to point out that if you pitch a barleywine on a yeast cake from a well made 70/- then that would technically be spent starter wort…right?

Not being a jerk at all.

How many yeasties in a week old, cold crash starter are still "alive"?
How many yeasties in a dry pack of yeast are still alive?

If I pitched a Barleywine on a 70/- yeast cake I can bet you all the money ever printed that there wont be 10% spent starter wort

Your talking about 2 quarts

 

[King of Cascade]

Not being a jerk at all.

How many yeasties in a week old, cold crash starter are still "alive"?
How many yeasties in a dry pack of yeast are still alive?

If I pitched a Barleywine on a 70/- yeast cake I can bet you all the money ever printed that there wont be 10% spent starter wort

Your talking about 2 quarts

How many yeasties in a week old, cold crash starter are still "alive"?

50% of yeast die when the food runs out?

you do the math

How many yeasties in a dry pack of yeast are still alive?

most if not all from what I understand.
I’m not very familiar with the drying procedure but they guarantee a certain cell count and I hope they are talking about “live cells"

If I pitched a Barleywine on a 70/- yeast cake I can bet you all the money ever printed that there wont be 10% spent starter wort

you missed the point...you would be drinking the spent wort (aka the 70/-)

 

[a10t2]

Yeah about 80% steep up each steep from a single colony.

Come again?

Would just like to point out that if you pitch a barleywine on a yeast cake from a well made 70/- then that would technically be spent starter wort…right?

Well, if you were oxygenating the 70/- during fermentation I don't think I'd call it "well made". And if you were I certainly wouldn't pitch on it without decanting the "spent wort".

Plus, by your logic that yeast cake would be at least 50% dead cells, right? For that matter, so would a smack pack.

 

[JohnMc]

Take a look at the two graphs on pg 5 of this pdf:
http://www.bdbiosciences.com/documents/Evaluation_of_Yeast_Viability.pdf
Granted, it's wine, but it's informative.

 

[passedpawn]

Take a look at the two graphs on pg 5 of this pdf:
http://www.bdbiosciences.com/documents/Evaluation_of_Yeast_Viability.pdf
Granted, it's wine, but it's informative.

Summary of graphs:

Yeast viability in wine drops about 2% over 2.5 weeks. Specific gravity goes from about 1.150 to 1.013 during that period, so the yeast was quite busy.

Essentially, there is almost no loss of yeast. At least in wine.

To relate this to the discussion above is difficult because assertion here is that there is a significant die-off within days of the fermentable sugar supply running out. The referenced graphs stop before the end of fermentation.

 

[JohnMc]

Yeast viability in wine drops about 2% over 2.5 weeks

The first graph shows the viability bouncing around mostly between 80-90%, I wouldn't feel comfortable with such fine distinction, the data are to noisy.

The referenced graphs stop before the end of fermentation.

Yeah, it looks like they went just to the end. It would be informative to go farther, unless the E&J Gallo folks didn't want them to. Still, the 'food' is pretty much gone by day 15. They might have stopped because the yeast are flocculating and going below the measurable cells/ml.

 

[a10t2]

What's crazy is the immense die-off (~90%) immediately after pitching. Osmotic shock from the 24°P must?

 

[babalu87]

The first graph shows the viability bouncing around mostly between 80-90%, I wouldn't feel comfortable with such fine distinction, the data are to noisy.
Yeah, it looks like they went just to the end. It would be informative to go farther, unless the E&J Gallo folks didn't want them to. Still, the 'food' is pretty much gone by day 15. They might have stopped because the yeast are flocculating and going below the measurable cells/ml.

Why does my Apfelwine take off like a rocket on 2nd generation?

I pour off the slurry and re-use half and its going crazy pretty quick AND is done faster.

 

[a10t2]

Why does my Apfelwine take off like a rocket on 2nd generation?

Because the yeast has flocculated and is concentrated in the slurry?

I think you guys are agreeing with one another.

 

[babalu87]

Because the yeast has flocculated and is concentrated in the slurry?

I think you guys are agreeing with one another.

:rockin:

I know who I'm not in agreeance with though

 

[JohnMc]

Why does my Apfelwine take off like a rocket on 2nd generation?

I pour off the slurry and re-use half and its going crazy pretty quick AND is done faster.

&

They might have stopped because the yeast are flocculating and going below the measurable cells/ml.

I should have said "...measurable cells/ml in suspension." There are a ton of live ones in the slurry.

 

[passedpawn]

:rockin:

I know who I'm not in agreeance with though

Err... me?

 

[KevinW]

It is funny to me how the yeast I buy that comes in a vial and has been in cold storage for weeks is still very healthy and happy when introduced into my wort!
Big difference between live, dead, and dormant yeast cells!

Starters are kind of like blood, most people need the red cells from blood and not the plasma. (red cells are the live guys that carry food and oxygen)
Cold crashing the starter is the easy way to seperate the yeast(cells) from the wort(plasma) that was created by the starter!
Where I work we use huge centrifuges to seperate the cells from the plasma, hmmm, maybe I can take my starters to work and run them throught the centrifuge!!
On second thought I will just use my fridge

 

[King of Cascade]

It is funny to me how the yeast I buy that comes in a vial and has been in cold storage for weeks is still very healthy and happy when introduced into my wort!
Big difference between live, dead, and dormant yeast cells!

Starters are kind of like blood, most people need the red cells from blood and not the plasma. (red cells are the live guys that carry food and oxygen)
Cold crashing the starter is the easy way to seperate the yeast(cells) from the wort(plasma) that was created by the starter!
Where I work we use huge centrifuges to seperate the cells from the plasma, hmmm, maybe I can take my starters to work and run them throught the centrifuge!!
On second thought I will just use my fridge

It is funny to me how the yeast I buy that comes in a vial and has been in cold storage for weeks is still very healthy and happy when introduced into my wort!

Apples and oranges dude. When white labs or wyeast package their yeast they do so to provide the most healthy yeast possible.

Starters are kind of like blood, most people need the red cells from blood and not the plasma.

I don’t give blood and never received it but don’t you get the plasma and blood cells together when getting a transfusion? If so how does this support decanting?

Cold crashing the starter is the easy way to seperate the yeast(cells) from the wort(plasma) that was created by the starter

The debate is not how to separate cells from wort, that’s the easy part but to maintain the health and viability of the separated cells.

 

[passedpawn]

First of all, the yeast die as the food is running out or has run out. After that a lot of variable come in to play but about half for the average homebrewer.

Did you ever find the source for this 50% assertion? I am very interested!

 

[King of Cascade]

Did you ever find the source for this 50% assertion? I am very interested!

Not yet. I have hundreds of Brewing magazines from over the years and it will take some time to find the one article.
Greg Doss briefly talked about the yeast health from a decanted starter vs. 15 hour starter but the slides are not on the AHA website yet.

 

[KevinW]

Apples and oranges dude. When white labs or wyeast package their yeast they do so to provide the most healthy yeast possible.]
Yes, they package their yeast to survive a certain amount of time with a predictable amount of cell loss under specific conditions. I cannot imagine too many brewers who make starters with the intention of leaving them in the fridge for a month or more!

What I am getting at is when making a starter you are increasing the volume of yeast to pitch and since the yeast is all you need then decant the beer off of your starter.

Once you put the starter in the fridge the yeast will go dormant and drop out of solution. The idea of crashing a starter is with the assumption you will use the yeast within a short period of time. In other words, the yeast should not sit long enough in the fridge to die off in an amount that will impact your fermentation.

 

[cruelkix]

So the take away from all of this:

Cold Crash your yeast at High Kraussen (the recommended time at which to pitch your starter as far as I have ever heard), decant, and pitch.

This makes sure that when you put your yeast into a dormant state that the cells are at their most viable point and that it hasn't run out of Big Macs/Food so none have started dying off. This is assuming that you dont want what is left over from the wort youused for your starter. Personally I use wort from my the actual brew im making the starter for and let my brew sit for 24 hours without yeast in it. Slightly risky for contamination pruposes, but I have had no issues.

 

[passedpawn]

In other words, the yeast should not sit long enough in the fridge to die off in an amount that will impact your fermentation.

Yes, of course that is how we all feel except King of Cascades. He says that there is a 50% die-off in two days, and that there is a source out there that has scientifically shown this to be true. He will submit some evidence to support this soon.

 

[KevinW]

Yes, of course that is how we all feel except King of Cascades. He says that there is a 50% die-off in two days, and that there is a source out there that has scientifically shown this to be true. He will submit some evidence to support this soon.

Oh thanks, I understand now, I must have missed that somewhere.

That is interesting though, I would imagine you could have a 50% die off if you don't take care of the little guys but otherwise I cannot wait to see the article