Author Topic: New starter procedure trial  (Read 33575 times)

Offline MerlinWerks

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Re: New starter procedure trial
« Reply #240 on: October 08, 2015, 05:22:07 PM »
Thanks Mark, pitching the slurry is what I have been doing for several batches now. I was initially searching for opinions on how many generations of 1450 I could continue to repitch (realizing there are host of variables) when I came across this thread.

When making a starter for 5 gal I would typically go 1.8L on stir plate, fermcap, cold crash, decant like many others. I was intrigued by the thought of pitching a smaller volume of starter wort at high krausen with yeast rarin' to go...

Offline denny

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Re: New starter procedure trial
« Reply #241 on: October 08, 2015, 05:54:34 PM »
I've gone as high as 6 generations with 1450.  Might have been able to get more out it, but I have no personal data.
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Offline MerlinWerks

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Re: New starter procedure trial
« Reply #242 on: October 08, 2015, 06:09:43 PM »
Thanks Denny...

Offline MerlinWerks

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Re: New starter procedure trial
« Reply #243 on: October 08, 2015, 07:34:35 PM »
... That volume should contain roughly 60 billion viable cells at two weeks...

Mark,

What criteria/formula did you use to determine this? I would like to calculate that in the future for yeast of varying age.

Thanks for all your help

S. cerevisiae

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Re: New starter procedure trial
« Reply #244 on: October 08, 2015, 09:04:08 PM »
What criteria/formula did you use to determine this? I would like to calculate that in the future for yeast of varying age.

I just used a few rules of thumb.  The counts are merely approximations, but all one needs is an approximation when it comes to yeast due to exponential growth.   I used Wyeast's cell count for thick slurry that contains 40 to 60 percent yeast solids, which is 1.2 billion cells per milliliter.  The maximum cell density for a 1L flask is approximately 200 billions cells.  I am assuming that the average commercial yeast culture has about 60 billion viable cells by the time it is pitched into a starter or wort.  I took 60 divided by 1.2, which gave me 50ml.  I then discounted the viability of the cropped yeast by 25%, yielding 50 / .75 = 66.67ml.  I then made it is an easy to measure value of 65 ml.  One can expect to grow between 1 billion and 1.5 billion yeast cells per gram of extract  A  1L 10% w/v (1.040) starter contains 100 grams of extract; hence, it will support the growth of between 100 and 150 billion new cells given enough O2 to support cellular health.  That growth range yields a ratio of roughly 2:1 new cells to old cells. 

Remember, the only way to get exact cell counts is to take a small volume of slurry or actively fermenting wort, dilute it to make counting easier, and count cells using a microscope and a hemocytometer.  Even then, the cell count is still approximate due to the error encountered when taking a sample.
« Last Edit: October 08, 2015, 09:12:38 PM by S. cerevisiae »

evil_morty

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Re: New starter procedure trial
« Reply #245 on: October 09, 2015, 01:44:32 AM »
once it's pure foam there isn't much more I can do right?

evil_morty

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Re: New starter procedure trial
« Reply #246 on: October 09, 2015, 09:31:00 AM »
8 hours since shaking with yeast:


evil_morty

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Re: New starter procedure trial
« Reply #247 on: October 09, 2015, 03:25:22 PM »
13.5 hours (still chilling my wort),  some yeast settling to the bottom.  I never really witnessed any crazy looking fermentation.  ambient temp 65F.


Offline dilluh98

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Re: New starter procedure trial
« Reply #248 on: October 09, 2015, 03:34:53 PM »
By the looks of it, you'll be just fine.

Offline denny

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Re: New starter procedure trial
« Reply #249 on: October 09, 2015, 04:01:04 PM »
13.5 hours (still chilling my wort),  some yeast settling to the bottom.  I never really witnessed any crazy looking fermentation.  ambient temp 65F.



Looks a lot like mind did.
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S. cerevisiae

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Re: New starter procedure trial
« Reply #250 on: October 09, 2015, 04:16:55 PM »
13.5 hours (still chilling my wort),  some yeast settling to the bottom.  I never really witnessed any crazy looking fermentation.  ambient temp 65F.

I would not judge the effectiveness of the technique by the size of the head on the starter.  The size of the head depends on the yeast strain.  Some strains will produce a large head while others will only produce enough to cover the top of the wort.  What you had is about as good as it is going to get.  Did you happen to take a photo immediately after shaking?

evil_morty

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Re: New starter procedure trial
« Reply #251 on: October 09, 2015, 04:19:47 PM »
13.5 hours (still chilling my wort),  some yeast settling to the bottom.  I never really witnessed any crazy looking fermentation.  ambient temp 65F.

I would not judge the effectiveness of the technique by the size of the head on the starter.  The size of the head depends on the yeast strain.  Some strains will produce a large head while others will only produce enough to cover the top of the wort.  What you had is about as good as it is going to get.  Did you happen to take a photo immediately after shaking?

I was mashing in, making a starter and kegging beer all at the same time :P

It was pure foam for about 5-10 minutes and then the head started to collapse.  I'd say the foam was at least 4x the volume of the starter after I shook it.

evil_morty

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Re: New starter procedure trial
« Reply #252 on: October 09, 2015, 06:02:59 PM »
so the yeast has been pitched.  I didn't cool it all the way down to 50F (wort temp) but I did get it somewhere between room and that.  the starter still smelled pretty much the same as what I'm used to (yeasty!).

evil_morty

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Re: New starter procedure trial
« Reply #253 on: October 09, 2015, 07:45:57 PM »
anyone want to place any bets on how many hours in I see airlock activity?  8)

Offline denny

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Re: New starter procedure trial
« Reply #254 on: October 09, 2015, 07:59:27 PM »
anyone want to place any bets on how many hours in I see airlock activity?  8)

within 18...how's that for loose?  :)
Life begins at 60.....1.060, that is!

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The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell