First Question on this Site- Gravity Issues

Discussion in 'General Brewing Discussions' started by Chauncey Beerman, Jun 10, 2014.

  1. Chauncey Beerman

    Chauncey Beerman New Member

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    Hello all,

    This is my first post on the forum.
    I have used the recipe editor and have gained a lot of knowledge perusing the site.

    I have conducted three brews so far- an extract blond ale, an all-grain special bitter, and an all-grain IPA the other day.

    I did not get great efficiency (48% or so) on my first all-grain; upgraded form a homemade pasta maker grain mill to a Cereal Killer and hit about 77% conversion on my latest IPA.

    I collected 7.5 gallons of wort after the mash and got a pre-boil gravity of 1.040, adjusted for a temp of 141F to 1.053 or so.
    After the 60 minute boil I had about 6 gallons and when cooled to approx. 72F, I got a gravity of 1.054.
    I was aiming for a pre-boil of 1.048 and an OG of 1.065. I recalled, after the fact, that I left behind about 1/4 gallon of wort at the sparge (worried about collecting too much- that may have been a mistake).
    How was I able to hit a pre-boil gravity so high (temp adjusted) and an OG only a tiny bit higher?

    Sorry if I didn't explain that very well, and thanks in advance!
    This site is great.

    Cheers,
    CB
     
  2. UgliestLemming

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    First thing to check is your equipment calibration - I once had a thermometer that read fine at lower temps - but was 15 degrees off at higher temps (this was before I got a thermoworks thermometer.) Hydrometers need to be checked too. Take a look at this blog post for tricks on looking at instrument calibration.

    http://www.brewersfriend.com/2010/12/19 ... esomeness/
     
  3. Ozarks Mountain Brew

    Staff Member

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    if your using someone's recipe, look close at the efficiency of that recipe first and change it lower, then add grains, hops to compensate until you get your brewing consistent. then set up your equipment settings to match what you think your wasting with water and absorption to get the site to work like your recipe calls for
     
  4. nzbrew

    nzbrew Active Member

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    Definately sounds like a measurement error with one of your gravity readings.

    There is a calculator on this site which tells you what should have happened:
    http://www.brewersfriend.com/dilution-a ... alculator/

    According to that, with your pre-boil gravity and volume, your post boil should have been what you expected :
     

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  5. Nosybear

    Nosybear Well-Known Member

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    Simple math: Measured gravity*original volume/final volume.
     
  6. Chauncey Beerman

    Chauncey Beerman New Member

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    Thanks for all the input, guys.
    The more I loook it over the more I think it's a matter of inaccurate equipment. I will have to calibrate it as per the link.

    Thanks again!
     
  7. TheZel66

    TheZel66 Member

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    the way your grain is crushed can dramatically affect your efficiency. make sure that when you crush your grains, you aren't leaving many grains uncrushed. While you don't want a powder (-> stuck mash), you do want the insides removed from the husks, and the kernels broken up a bit.

    I changed my grain mill separation and got a 15% increase in efficiency.
     
  8. Chauncey Beerman

    Chauncey Beerman New Member

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    Indeed. I learned this firsthand by breaking down and buying a mill. My pathetic pasta maker grain mill (trying to be as DYI as I could) yielded an efficiency around 44-48%. I got 77% with my new mill, so I was thrilled. Plus it saved a ton of time as well.
     
  9. nzbrew

    nzbrew Active Member

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    Were you 'sampling' while brewing - it could be the calibration of the 'eye-ometer' taking the readings! I have fallen into this trap a couple of times...........

    :cool:
     
  10. Chauncey Beerman

    Chauncey Beerman New Member

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    Sadly, I only "sampled" one from a previous batch!
     
  11. Chauncey Beerman

    Chauncey Beerman New Member

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    Well, after bottling, priming, and waiting I can say that my hydrometer must have been acting up- I took another reading after fermentation and hit the FG on the mark. And the cascade-columbus IPA is wonderful.
     

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