OG/FG all grain calculator discrepencies

Discussion in 'Calculator Support Forum' started by Retired trucker 2014, Jul 27, 2021.

  1. Retired trucker 2014

    Joined:
    Jul 19, 2018
    Messages:
    20
    Likes Received:
    9
    Trophy Points:
    3
    Location:
    Pacuarito, Pérez Zeledón, San Jóse, Costa Rica
    When estimating an all grain recipe with the OG/FC Calcutator then in puting in a new recipe the preboil -post boil and abv do not match. In fact the recipe is always ten to fifteen points higher. Why is this?
     
  2. Yooper

    Yooper Administrator
    Staff Member

    Joined:
    Nov 16, 2013
    Messages:
    2,745
    Likes Received:
    1,934
    Trophy Points:
    113
    Gender:
    Female
    Occupation:
    Happily retired
    Location:
    Upper Michigan/Florida
    I don’t know what you mean- can you give me a link or a screenshot so I can see what’s going on?
     
  3. WesBrew

    WesBrew Well-Known Member

    Joined:
    Feb 18, 2021
    Messages:
    175
    Likes Received:
    306
    Trophy Points:
    63
    Gender:
    Male
    Location:
    The Free South
    #3 WesBrew, Jul 28, 2021
    Last edited: Jul 28, 2021
    Check that your pre-boil and post-boil sizes are correct in the recipe editor . i have a similar issue whenever i scale a receipe down to a smaller batch size, BF does not change the post boil size and it throws off the OG prediction. I have to change the post boil size manually to fix it.
     
    Josh Hughes likes this.
  4. Retired trucker 2014

    Joined:
    Jul 19, 2018
    Messages:
    20
    Likes Received:
    9
    Trophy Points:
    3
    Location:
    Pacuarito, Pérez Zeledón, San Jóse, Costa Rica
    It's not the recipe editor . When I brewed the recipe it's fg was within 1 point. Somehow the og/fg calculator is at fault.
     
  5. Retired trucker 2014

    Joined:
    Jul 19, 2018
    Messages:
    20
    Likes Received:
    9
    Trophy Points:
    3
    Location:
    Pacuarito, Pérez Zeledón, San Jóse, Costa Rica
    Screenshot_20210728-132401_Opera.jpg Screenshot_20210728-132144_Opera.jpg
     
  6. WesBrew

    WesBrew Well-Known Member

    Joined:
    Feb 18, 2021
    Messages:
    175
    Likes Received:
    306
    Trophy Points:
    63
    Gender:
    Male
    Location:
    The Free South
    #6 WesBrew, Jul 29, 2021
    Last edited: Jul 29, 2021
    Check that the batch sizes, start and finish are the same in both the calculator and the recipe editor, and the efficiency is the same. using the calculator tool with 5gal batch size/75% efficiency i get .037og post boil and 3.5%abv with a medium attenuation yeast
    when i put that into the recipe builder-its .039OG, finishes at 3.8%, so pretty close.
     
  7. Pricelessbrewing

    Pricelessbrewing QA Software Tester
    Staff Member

    Joined:
    Jun 8, 2016
    Messages:
    1,021
    Likes Received:
    760
    Trophy Points:
    113
    Gender:
    Male
    There's a couple reasons the standalone calculators may be slightly different, but overall the recipe builder is the recommended app. The calculators make several simplifications to various degrees, so they may not be as accurate or reliable as the full recipe builder.

    For more specifics though we really do need a link to the full recipe, and all of the data you've entered into the calculator. Just the little snapshot included isn't sufficient.
     
  8. Bel Air Brewing

    Bel Air Brewing New Member

    Joined:
    Sep 14, 2021
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    1
    #8 Bel Air Brewing, Sep 14, 2021
    Last edited: Sep 14, 2021
    I used the full recipe builder. It was way off! My OG was predicted at 1.056. It came in at 1.071.The app is useless.
    When checked against a commercial breweries recipe which was 1.058 OG, the Brewer’s Friend Recipe Builder showed 1.048.
    What accounts for this major flaw in the program?
     
  9. Donoroto

    Donoroto Well-Known Member

    Joined:
    Jun 21, 2020
    Messages:
    1,613
    Likes Received:
    2,517
    Trophy Points:
    113
    Occupation:
    Retired Engineer
    Location:
    Atlanta
    A lot depends on accurate inputs and settings. Please make your recipe public and provide a link to it, thanks.
     
    Megary likes this.
  10. Bel Air Brewing

    Bel Air Brewing New Member

    Joined:
    Sep 14, 2021
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    1
  11. Yooper

    Yooper Administrator
    Staff Member

    Joined:
    Nov 16, 2013
    Messages:
    2,745
    Likes Received:
    1,934
    Trophy Points:
    113
    Gender:
    Female
    Occupation:
    Happily retired
    Location:
    Upper Michigan/Florida
    1.058 for 24 pounds of grain in 10.5 gallons finished wort seems about right if your efficiency is 70%. You got 1.071?
     
  12. Donoroto

    Donoroto Well-Known Member

    Joined:
    Jun 21, 2020
    Messages:
    1,613
    Likes Received:
    2,517
    Trophy Points:
    113
    Occupation:
    Retired Engineer
    Location:
    Atlanta
  13. Bel Air Brewing

    Bel Air Brewing New Member

    Joined:
    Sep 14, 2021
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    1
    Three 15.5 gallon stainless kettles. Continuous recirc of the mash. Sparge is gravity feed.
     
  14. Bel Air Brewing

    Bel Air Brewing New Member

    Joined:
    Sep 14, 2021
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    1
    Yes, the refractometer indicated 1.071, with the wort at 74 F.
     
  15. Donoroto

    Donoroto Well-Known Member

    Joined:
    Jun 21, 2020
    Messages:
    1,613
    Likes Received:
    2,517
    Trophy Points:
    113
    Occupation:
    Retired Engineer
    Location:
    Atlanta
    Nice. Is it possible your brewhouse efficiency is greater than 70%? A friend with a similar system regularly exceeds 80%. Try fiddling with the brewhouse efficiency number until you see a 1.071 OG, could your efficiency possibly be that high?

    Not saying it is, but truly wondering. My brewzilla regularly delivers 78%. At least, when I use 78 in my recipes it comes out very close.
     
  16. BarbarianBrewer

    BarbarianBrewer Well-Known Member

    Joined:
    Mar 12, 2017
    Messages:
    849
    Likes Received:
    1,592
    Trophy Points:
    93
    Location:
    Milwaukee, WI
    The first problem is easy to solve: Brewer's Friend also shows an OG of 1.058. It's the pre-boil gravity that is 1.048.
    upload_2021-9-15_20-21-46.png

    For the higher than expected actual OG...just guessing here: Could the Wort Correction Factor be off? Maybe greater boiloff? Awesome efficiency? All of the above?
     
  17. Bel Air Brewing

    Bel Air Brewing New Member

    Joined:
    Sep 14, 2021
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    1
    That 1.048 number came from a commercial recipe that I plugged in for comparison. The beer came in at 1.058.
    I do triple step infusion mashes - 122 for 30 minutes, 146 for 20 minutes, and 158 for 20 minutes. Mash out at 170.
    Maybe this allows greater efficiency?
    Or maybe I misread the refractometer? Unlikely, however.
     
  18. Bel Air Brewing

    Bel Air Brewing New Member

    Joined:
    Sep 14, 2021
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    1
    After adjusting the efficiency to 90%, the predicted OG was 1.071.
    Perhaps my system is more efficient than we thought.
     
  19. BarbarianBrewer

    BarbarianBrewer Well-Known Member

    Joined:
    Mar 12, 2017
    Messages:
    849
    Likes Received:
    1,592
    Trophy Points:
    93
    Location:
    Milwaukee, WI
  20. Donoroto

    Donoroto Well-Known Member

    Joined:
    Jun 21, 2020
    Messages:
    1,613
    Likes Received:
    2,517
    Trophy Points:
    113
    Occupation:
    Retired Engineer
    Location:
    Atlanta
    Perhaps, but perhaps not. I would certainly think it is higher than 70 though.

    For that commercial recipe, it would satisfy my curiosity to see what I got if I actually brewed it.

    I guess my point is that, at least for me, the recipe builder* has been pretty close for me in well over a dozen recipes.

    *Ha! Once I came to understand it!!
     

Share This Page

arrow_white