Yeast Cell Count When Harvesting

Discussion in 'Homebrewing' started by TooHopTooHandle, Oct 17, 2017.

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  1. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    So I recently just started harvesting yeast. Currently I just top cropped some yeast from my fermenter. Yeast used was London Ale III 1318.
    My question is how do I calculate what the cell count will be after I make a starter with this. Starter size is about 1700ml and there is also yeast nutrient in the starter. I will take this starter and break it down into a few jars to make starters from those. So I need to know how to calculate the cell count if there is a way so I know what size starters to make for proper pitches.[​IMG]
    Here is the starter I made lol has only been going for 10 minutes
     
    #1 TooHopTooHandle, Oct 17, 2017
  2. pweis909

    pweis909 Grand Pooh-Bah (3,250) Aug 13, 2005 Wisconsin
    Pooh-Bah

    You can use a calculator like this:
    https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
    I use this calculator to tell me how to make a starter, but really, what it does is provide a cell count estimate based on how you make your starter. I think it does what you are looking for.

    Or if you are into it, you can use a microscope, hemocytometer, and one of several staining techniques to directly count cells to estimate pitch rates. If you get good, this is bound to be the more reliable estimate, but it takes an investment, both the tools and the time. I got the tools but not the time, so it's brewersfriend for me.
     
    #2 pweis909, Oct 17, 2017
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  3. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    Thanks for the Input, I use the same calculator also. When using a yeast packet to make your starter that calculator works well to estimate because you can estimate your cell count based on how many cells are in package and date, but how do I get a estimate cell count off the yeast that I top cropped from my fermenter and made a starter with? Is there any software that can some what provide that estimate? I understand that this is probably a shot in the dark because in order to do that we would need to know how much/cell count of the yeast taken from fermenter.
     
    #3 TooHopTooHandle, Oct 17, 2017
  4. chavinparty

    chavinparty Zealot (653) Jan 4, 2015 New Hampshire

    I think you can estimate based on how much yeast is on the bottom once it settles out
     
    #4 chavinparty, Oct 17, 2017
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  5. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    Well that is out the window lol because I immediately pitched the top cropped yeast into the starter pictured at the top of this post
     
    #5 TooHopTooHandle, Oct 17, 2017
  6. chavinparty

    chavinparty Zealot (653) Jan 4, 2015 New Hampshire

    Yeah but if you were going to let it ferment out you could see how much yeast settles to the bottom and get a rough idea of how much yeast. I forget where I read about this... obviously a crude estimation
     
    #6 chavinparty, Oct 17, 2017
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  7. pweis909

    pweis909 Grand Pooh-Bah (3,250) Aug 13, 2005 Wisconsin
    Pooh-Bah

    Short of doing viable cell counts, I think prescriptive formulae will always be elusive here. Those calculators work for starters, but they are still a shot in the dark. And starters are pretty controlled, but as you use them to build a beer, there are fewer controls that apply across all homebrewers (we don't all oxygenate the same, we don't all ferment at the same temp we don't hop the same, etc), which I think would make a formulaic prediction even less applicable. Still, you've probably seen the Mr Malty calculator. It has a tab for pitching yeast from a slurry. But there is some fudge-factoring going on there, like plugging in yeast concentration and non-yeast percentage. Maybe it is just a matter of finding the fudge factors that work best for you most of the time? I've never bothered with this, mostly because I don't repitch all that often.
     
    #7 pweis909, Oct 17, 2017
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  8. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    I also read about that, but the info was related to before pitching it. So after I cold crash it and make sure there is no trub in there I will see what I have in there at the bottom. I guess I could compare it to what was at the bottom of my flask when I made the same size starter(glad I took a pic of the flask after cold crash) from the original smack packet. I know those results will be a lot different because of all the variables involved, but I at least can have some sort of starting ground to work with and brew the same exact batch and pitch the same size starter of this top crop that I pitched in the previous beer made from the smack pack and monitor the gravity reads each day like I have been with this one. So hopefully my detailed note taking will pay off for once lol
     
    #8 TooHopTooHandle, Oct 17, 2017
    Last edited: Oct 17, 2017
  9. PortLargo

    PortLargo Pooh-Bah (1,831) Oct 19, 2012 Florida
    Pooh-Bah

    A couple of tidbits I can contribute:
    When you harvest used yeast or top crop a starter you potential change the yeast characteristics. When you recover the "fast-flocc'ers" or the "top-crop'ers" this may not truly represent the yeast strain. A technique that may give better results is to make a starter larger than what you need. Then give it a hard shake and immediately pour off the XX percent that is overage . . . this should more represent the strain. Use this extra for making a starter your next brew day. I typically get 3 - 5 restarts out of a new packet. Most common problems when re-starting is infection or over-attenuation or loss of characteristics.

    For calculating how many viable cells per ml of yeast solids I estimate 2 Billion cells/ml (of re-started yeast). This is yeast solids that have settled, not the liquid above. This is somewhat a shot in the dark, but there are studies that make this an educated guess. Remember, the older the yeast the more dead cells that stay in the starter. You'll see 'em, but they aren't gonna contribute to fermentation. As a reference, new healthy yeast runs about 5 billion cells/ml(of solids).

    To measure these smaller quantities in a 2L flask I add a piece of masking tape to make a 100ml mark as a reference. For long term storage in a mason jar you should have ml markings on the side, don't forget to adjust for time. After about a dozen times you develop a feel for how many viable cells are present in the solids. My process is fairly accurate using the 2B/ml figure.
     
    #9 PortLargo, Oct 17, 2017
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  10. DrMindbender

    DrMindbender Initiate (0) Jul 13, 2014 South Carolina

    I harvest yeast and bugs from cakes that I've just racked off of...I scoop small jars of yeast, usually 3-4, from the cake before I add fresh wort on top of it and save the jars for future brews. These jars are usually 8-12 oz canning jars and the viable yeast settles to about a tenth of the jar. This has been fine for me to use in future batches without making a starter and I havent had any issues with selective pressure changing the characteristics of the yeast or bugs. I'm sure making a starter would help out, but I'm fine with direct pitching these jars and having a slight lag phase instead. I've done this for many many years and never have any issues with off flavors or anything else.
     
    #10 DrMindbender, Oct 17, 2017
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  11. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    Thank you for all your input it is greatly appreciated! I will be brewing the same grain/hop bill and process for a few brews back to back so I can try to test this yeast out and see how it compares to yeast from the packet to what I cropped. It will either go good, bad, or ok lol
     
    #11 TooHopTooHandle, Oct 17, 2017
  12. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    Since I instantly pitched my top crop into about a 1.7L starter I am gonna divide into some 8oz mason jars. When I originally had this yeast smack pack I made a starter and split it into some jars. Using the yeast calculator I think each jar I made contained an estimate of 50bil cells (don't have my notes with me at work). I now have those jars in the fridge. I decanted almost all of the liquid I could before I put them in those jars and topped them off to the brim with sterilized water. Now after sitting for a few days the yeast cake has settled nice and solid to the bottom. So after I jar up this starter from the top cropped batch and let the cakes settle I should be able to get some what of an estimate on cells in the jar by placing it next to the other jar and comparing the cake size. Like I stated earlier I know a lot of other variables come into play since this isn't yeast directly from the packet, but I'm hoping I can some what get a ball park estimate on cells per jar after all of this lol.
     
    #12 TooHopTooHandle, Oct 17, 2017
  13. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    Ok so I have some pictures to compare the yeast I collected from a starter made with a yeast packet and a starter made with the top cropped yeast. Both starters were approximately the same size 1.75L. So using the yeast calculator I produced around 294bil cells from my yeast packet starter and split it into 7 jars equally as I could. So each jar yielded approx 42bil cells. I then combined 2 jars together for 6 of the jars leaving me with 3 double jars and kept 1 to make a starter for brew. So the doubled up jars contained approx 84bil cells. Here is a pic of the top cropped yeast starter jar and the yeast packet starter jar [​IMG]
    Jar on left is top crop and the right is yeast packet. So if calculating by yeast density the jar on the left has approx twice the amount of yeast as the one on the right, therefore giving me approx 168bil cells. What are your thoughts on this logic? Obviously there are diff variables involved as one yeast is from a packet and the other is from top crop, but I thought this might be the best way to approx how much yeast collected.
     
    #13 TooHopTooHandle, Oct 19, 2017
  14. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    #14 TooHopTooHandle, Oct 20, 2017
  15. chavinparty

    chavinparty Zealot (653) Jan 4, 2015 New Hampshire

    It looks to me like there is twice as much yeast in the jar on the left. Sound logic
     
    #15 chavinparty, Oct 20, 2017
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  16. utahbeerdude

    utahbeerdude Maven (1,374) May 2, 2006 Utah

    Sort of off topic, but a drop of Fermcap-S will keep the foam from getting out of hand in your starters. I put a drop in all my starter worts before boiling. It keeps the boiling wort from foaming up and the starter from also foaming. Cheers!
     
    #16 utahbeerdude, Oct 20, 2017
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  17. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    yeah lol my buddy was giving me shit about that also, so its on my list of things to get. I cant add it to the starter wort boil because I have like 20 premade jars of starter wort already, but its safe to just put a drop in the flask?
     
    #17 TooHopTooHandle, Oct 20, 2017
  18. utahbeerdude

    utahbeerdude Maven (1,374) May 2, 2006 Utah

    Sure, you can add it anytime. It's just a surfactant (simethicone) that breaks up bubbles.
     
    #18 utahbeerdude, Oct 20, 2017
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  19. TooHopTooHandle

    TooHopTooHandle Initiate (0) Dec 20, 2016 New York

    thanks :slight_smile: cheers!
     
    #19 TooHopTooHandle, Oct 20, 2017
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