Harvested Yeast Starter Layers

Discussion in 'Homebrewing' started by mclaughlindw4, Oct 11, 2014.

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  1. mclaughlindw4

    mclaughlindw4 Initiate (0) Jul 2, 2009 Maine

    I know there is info already on this but here goes... I've started making larger starters and saving about 500 mL of the yeast. Below are pics of (from left to right) WY1469, WY3711, WY1335.

    The two english have the dark layer on top and the white layer on the bottom and the 3711 is the other way around. I don't know that there should be much trub since it was just starter wort. They were all made on a stirplate.

    So from what I've read, the yeast is the creamy white layer and the trub settles to the bottom. Except for the english strains the creamy white layer is on the bottom. So I guess I am confused as to what I am looking at here. I was thinking about just using all of it (minus the liguid) to make starters when I go to use the beer, Does that sound ok? I read an article today where someone determined that yeast viability is exactly the same in every layer.

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  2. psnydez86

    psnydez86 Initiate (0) Jan 4, 2012 Pennsylvania

    I wouldn't worry about that little bit of trub. I think since the English strains are more flocculent than 3711 the yeast dropped out faster than the trub and the opposite happened with 3711.

    Rdwahahb
     
  3. PortLargo

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

    I say use it all.

    But are you sure about saving 500ml? From the photo I'm seeing about 50ml. Five hundred ml would be over a pint (16+ oz) and would be probably exceed 1 trillion cells.
     
  4. skivtjerry

    skivtjerry Pooh-Bah (1,865) Mar 10, 2006 Vermont
    Pooh-Bah

    First, as PortLargo said, your actual yeast is about 40-80ml of slurry... plenty if it's healthy, I'd not worry too much about the layering unless it has sat a couple weeks. Viability is indeed the same (on a % of total cells basis) in every layer, including the liquid layer on top; it's just that some layers contain a lot more yeast cells.
     
  5. inchrisin

    inchrisin Pooh-Bah (2,013) Sep 25, 2008 Indiana
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    Decant the beer off the top. Stir, pitch into a session beer within 2 weeks.

    If later, decant beer off top, make starter, let starter finish, put in the fridge for 3 days. Decant the beer again off the top and add to beer within 2 weeks.

    Use the sediment. No need to split hairs.
     
  6. mclaughlindw4

    mclaughlindw4 Initiate (0) Jul 2, 2009 Maine

    I saved 500 mL of the starter (those are pint ball jars). So I don't know exactly how much yeast is volumes. I've just been using math to calculate the yeast and not bothering with measurements. For example the 1469 I made a 1.5 mL starter to get 220 billion cells, I decanted 500 mL of wort, swirled the yeast back in suspension, and split it into two 500 mL ball jars so I should have roughly 110 billion per jar.
     
  7. PortLargo

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

    We're saying the same thing, just differently. The liquid part of your sample has almost no yeast remaining, the slurry at the bottom is the good stuff. My guideline is to estimate ~2 billion cells/ml (of slurry) which is very close to what you have estimated through the starter process (I'm using quantity based on photo). I say you are in great shape to decant/pitch what you have. I would caution to take into account loss of active yeast if you delay more than a week or two and anything over that would probably benefit from re-starting. Sounds like you have a good technique to boost your count.

    As for the white/tan layers, I see the same thing based on different strains. I'm not aware of any method to separate them, so it all goes in the fermentor for me.

    It's never happened to me, but others will recommend leaving the jars sealed loosely . . . just in case those little guys get active again . . .
     
  8. mclaughlindw4

    mclaughlindw4 Initiate (0) Jul 2, 2009 Maine

    How do you get an accurate measure of the volume of yeast? I would need to find something other than these jars to be able to measure that volume of yeast on the bottom.
     
  9. PortLargo

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

    I suppose a graduated beaker would be best for this, but I would rather not have the extra step involved. So I just use the graduated marks on the mason jars. From your photo, it looks like the jar on the right has slurry about half-way up to the 100ml line. Not pretending this is really accurate, but it seems to give a ballpark figure that works out okay.
     
    psnydez86 likes this.
  10. mclaughlindw4

    mclaughlindw4 Initiate (0) Jul 2, 2009 Maine

    Sounds good. I should start taking note of the volume in addition to my calculating it because I a sure the more I keep a strain going my calculating it is gonna end up being way off.
     
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