First runnings and Original Gravity

Discussion in 'Homebrewing' started by pittvkyle7, Apr 17, 2016.

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  1. pittvkyle7

    pittvkyle7 Initiate (0) Apr 16, 2007 Connecticut

    I batch sparge, and I regularly check the gravity of my first runnings. At first I did this in order to gather more data on brew days, but now I'm noticing that the gravity of my first runnings is close (it's always above by a few) to my predicted Original Gravity. I can almost use the First Runnings to predict the gravity after the boil.

    Has anyone else noticed this relationship? Or know of the reason for the similarity in numbers?
     
    #1 pittvkyle7, Apr 17, 2016
  2. GreenKrusty101

    GreenKrusty101 Initiate (0) Dec 4, 2008 Nevada

    First runnings are less dilute than second runnings, but haven't been boiled off yet to get an even higher OG...I think it's covered in Nostradamus' 15th Quatrain :slight_smile:
     
    #2 GreenKrusty101, Apr 17, 2016
  3. MostlyNorwegian

    MostlyNorwegian Pooh-Bah (2,236) Feb 5, 2013 Illinois
    Pooh-Bah

    I use two pots for my boil set up, and I did what I guess would be a batch sparge with my most recent one. Comes out great with two pots, and cuts down my brewday by over an hour, so I will be trying it more in the future.
    Those were 1075 first runnings (quick), and 1036 second runnings (slow enough that I finished about 15 minutes before f/o.) The blend was nearly spot on for what my intended og was, and life was good.
     
    #3 MostlyNorwegian, Apr 17, 2016
  4. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    It's a coincidence that's happening because of the particular volumes of your first and second runnings and your post boil volume. If you were to mash at a different thickness, or if your boil-off rate was different, the coincidence would go away. It's all about volumes and concentrations.
     
    #4 VikeMan, Apr 17, 2016
    pweis909 and inchrisin like this.
  5. pittvkyle7

    pittvkyle7 Initiate (0) Apr 16, 2007 Connecticut

    That's what I figured, but it has happened several times, so I wondered if anyone else noticed it.

    I've also wondered about a way to measure the efficiency of the first runnings and second runnings separately as a way to check the effectiveness of each of the equal batch sparges.
    For instance: I pulled 62% of my anticipated efficiency on the first runnings. And 33% of my anticipated efficiency on the second runnings. Leaving me with 95% of the efficiency I was aiming for.

    I guess I don't know why I'm looking into these numbers so much! I'm just trying to figure if there is something to be learned here!
     
    #5 pittvkyle7, Apr 17, 2016
  6. NiceFly

    NiceFly Initiate (0) Dec 22, 2011 Tajikistan

    Try brewing an OG 100 beer and see if it holds. I have found that my first runnings max out between 70 and 80.
     
    #6 NiceFly, Apr 18, 2016
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