Diacetyl rest gravity Brix conversion issue

Discussion in 'Calculator Support Forum' started by MugenCage, Apr 13, 2021.

  1. MugenCage

    MugenCage New Member

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    I added a Diacetyl Rest in my brew log. The Brix calculator converted my 10.8 reading to SG-1.043. When I add a Sample to the brew log of the same 10.8 reading I get a SG-1.020 conversion. I used the Refractometer Calculator to confine my readings. If I enter 10.8 under Part I: OG Brix WRI Correction I get a SG-1.043 conversion. If I enter 10.8 under Part II: FG Brix WRI Alcohol Present (with my OG of 1.084) I get a SG-1.020 conversion. Shouldn't the Brew Log treat a Diacetyl Rest more like an FG than an OG since it is nearing the end of fermentation?
     
  2. Yooper

    Yooper Administrator
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    The FG is the final gravity- that is, the ultimate ending SG of the beer when it’s 100% done.
     
  3. Mont Y. Märzen

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    I could be misunderstanding, but like the OP, I would think a Diacetyl Rest entry would be treated the same as a Sample.

    The Sample entry has a field for the OG which is automatically pulled in from the Brew Day Complete entry. It uses this to correct the BrixWRI for alcohol present.

    If Sample log entries do this compensation before FG, why doesn't the Diacetyl Rest entry? (it's just a specifically named sample point after all)
     
  4. Minbari

    Minbari Well-Known Member

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    Brix is brix! It is either one or the other. Presence of alcohol makes no difference. It doesn't matter where it is in the process. 10.8 is 10.8

    10.8 is 1.043.

    Only exception is if you used a refractometer to determine the brix reading, then you have to adjust it. The calculator shouldn't be making that assumption though
     
  5. Mont Y. Märzen

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    That's the point. Yes, using a refractometer.

    Read over the BF article about BrixWRI. The Sample type log entry *does* adjust. But for some as yet unexplained reason, the Diacetyl Rest type (just a specific sample) does not.
     
  6. Minbari

    Minbari Well-Known Member

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    But that was my point. Unless you specify that the reading came from a refrac, it doesn't need converting
     
  7. Mont Y. Märzen

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    You are not listening.

    Yes, the reading comes from a refractometer, and yes, that is specified.

    There are three options when entering a gravity reading:
    • Specific Gravity
    • Plato
    • Refractometer (BrixWRI)
    But when choosing 'Refractometer (BrixWRI)' the adjustment for alcohol is not being made, for a Diacetyl Rest sample entry, but *is* being made for a generic Sample entry.
     
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  8. Minbari

    Minbari Well-Known Member

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    Ahhh thanks for the clarification. I was under the impression it didn't ask what the source was
     
  9. Pricelessbrewing

    Pricelessbrewing BF Software Manager
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    Any step that is occuring after pitching yeast that accepts the 'Refractometer (BrixWRI)' as a sample reading, should probably be treated as mid-fermentation and adjusted accordingly. I'll open a ticket, thank you for reporting and explaining thoroughly @Mont Y. Märzen
     
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  10. Mont Y. Märzen

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    @MugenCage is the OP, but I'm happy to verify and clarify. Thanks for looking into it.
     
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