First AG

Discussion in 'General Brewing Discussions' started by Nugnut, Sep 28, 2017.

  1. Nugnut

    Nugnut Member

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    Okay I just finished my first AG. A Sierra Nevada.

    Couple of stuff ups but mostly due to an infra red thermometer, but lesson learned and will get a thermopen or similar. Any recomendations.

    What I can't get my head around is how can I have a conversion of 114.1%. What have I done wrong Do you put in the volume you put in the MLT or what ended in the boil. I put what ended in the boil.

    I ended with

    Conversion: 114.1%
    Pre-Boil: 98% 37 ppg
    Ending Kettle: 79% 29.7 ppg
    Brew House: 63% 23.8 ppg
    Help, what have I done wrong?
     
  2. HighVoltageMan!

    HighVoltageMan! Well-Known Member

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    I'm not sure how you can calculate a conversion efficiency.
    I check my efficiency after I have lautered and sparged. I usually have 7 gallons or so and the gravity varies just before the boil. It helps me determine how long the boil will be. I never brew for a specific volume, rather I brew and boil for a target gravity.

    There's no way to get above 100%. But your "ending kettle" and brew house seem reasonable.

    I typically get 80-85% efficiency into the boil kettle prior to the boil. My efficiency will be lower if I measure at the fermenter due to wort loss (hops soak up wort, spilling, etc.)

    The main reason I check it is to see if I'm on target to hit my gravity. If it's too high, I add some water. Too low means a longer boil. Other than that, it's really not very important.
     
  3. Nosybear

    Nosybear Well-Known Member

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    Calculating conversion efficiency: You have to make some assumptions. Easiest way is to use gravity points, ppg or pkl, depending on your units of measure. Each grain delivers a certain amount of "points" per gallon - Here's a table:

    http://howtobrew.com/book/section-2/what-is-malted-grain/table-of-typical-malt-yields

    Multiply the number of pounds of malt times the corresponding number in the "Max ppg" column. Do this for each malt then add the results. This will give you your theoretical yield in points. Now take the OG in points (OG-1)*1000, multiply that times the volume to get your actual yield. Divide actual by theoretical and you get your efficiency.

    If you got 114%, something is wrong. The calculator goes wonky if you add sugars.
     
  4. Nugnut

    Nugnut Member

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    Thanks guys. its all dutch to me. Tastes and smells good to me at this stage.
     
  5. Ozarks Mountain Brew

    Staff Member

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  6. Trialben

    Trialben Well-Known Member

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    Conversion efficiency is total liquor used in mash including sparge water -stir well run some wort through tap some then take a sample and let it cool in fridge whilst bringing your wort to boil. Pre boil is same as is your pre boil Gravity this is the same as conversion. Your post boil Gravity is as it says gravity of wort after boil losses. Finally brewhouse is what's in your fermentor after everything is done and dusted. I aim for a 21lt ish fermentor volume after all my losses to get 19lt of kegged beer. Hope this helps Nugnut;)
     
  7. J A

    J A Well-Known Member

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    I ignore mash efficiency and go for a pre-boil efficiency. It's closer to the real world without a lot of equipment profile settings to consider. and I've never gotten accurate readings from pre-boil wort. It always seems too high. Never have figured out why, but once I got my system figured out and dialed in, it's unimportant because my efficiency is consistent and I can use the calculator with confidence. Ultimately your post-boil readings are the only ones that matter. The volume and gravity of the wort after boiling tell you what your OG is. Those are the numbers that the calculator uses to get to efficiency percentage (assuming that you use the "ending kettle" setting).
     
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  8. Nosybear

    Nosybear Well-Known Member

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    Okay, back to the original question: I don't think anything is wrong, just some input error or some quirk of the efficiency calculator. I find that whenever I do any kind of late addition, I get wonky conversion numbers. Not having access to the recipe, I can't tell if that's the case but it looks like, by the end of the day, everything was in order. Conversion efficiency is the ratio of what you got to the theoretical maximum extract. You could have entered either gravity or volume wrong and have gotten the result you got. Go back and check your entries: Did you use the post-boil gravity in the beginning kettle entry? Or maybe the volume entry was too high? Either way, as I said, it looks like things came out right. RDWHAHB.
     
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