Problem with calculation when using custom fermentable

Discussion in 'Recipe Editor' started by Sjakkt, Jul 18, 2014.

  1. Sjakkt

    Sjakkt New Member

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    Hi BrewersFriend.

    First: great site - love it.

    Second: I wanted to adjust my fermentables as I think your German Pale Ale is a bit high on PPG (at least compared to Bestmalz own stats which I'm using), its even higher than your Wheat malt PPG(!)... anyways: when I add custom fermentable and plot in PPG and Lovibond, the OG goes through the roof - same amount of malt (4 kilos in my recipe) and even lower PPG. I then removed it and added custom again and used the same numbers as you are using (39 PPG), and the OG is still way higher... so unless I've missed something it seems there some calculation errors there? I'll upload screenshots so you know what I'm talking about.

    Thanks in advance for any help

    Best regards
     

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  2. Austin

    Austin Member

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    Thanks for the information with the screen shot. I'm having a tech look at it.
     
  3. kblankenship11

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    I've noticed the same thing as well. I've found another issue which may be in relation to some formula being flubbed when working with custom fermentables.

    Here's a picture of my custom fermentable, 35 ppg:


    Here's the same recipe just changed to the standard 6-row with the same ppg:


    The weird thing is when I add my gravity samples the percentage is crazy. Here's an example of what I got from my brew session using the custom fermentable in my recipe:
     

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  4. Serge Marx

    Serge Marx New Member

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    Hey, I'm having the exact same issue: my custom malt has same PPG as American Ale 2 Row, but switching between the two shows a massive difference in calculated gravity (1.071 (custom) vs 1.053 (AA)

    Is this a recurring issue, or unfixed since last year when reported on this thread?

    Loving BF, but with new malts appearing faster in the real world faster than they do on the site, we need the custom ferms option to work. pretty serious bug, which could have caused a lot of confusion had I not double checked my numbers were entered correctly.

    Cheers
    Rhys
     
  5. Austin

    Austin Member

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    Rhys can you post a few screen shots as to how the discrepancies are currently showing? It will help to see what you are seeing.

    Thanks
     
  6. Serge Marx

    Serge Marx New Member

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  7. Serge Marx

    Serge Marx New Member

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    Any progress on this issue?

    cheers,

    Rhys
     
  8. Serge Marx

    Serge Marx New Member

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    Hey, I'm sure I'm not the only one seeing this problem - has the BF team been able to replicate? Can someone else give it a try to see? Would be nice to see this bug solved.
     
  9. Josh (Brewer's Friend)

    Josh (Brewer's Friend) Administrator
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    Hi guys, I apologize for the lack of reply on this. I'm still getting caught up with some older issues and haven't gotten to this one yet. I just did some testing and I'm wondering if this is related to the use of the "Mashed" checkbox on custom fermentables. Have you guys tried using that? By default it is unchecked, which means that custom fermentables aren't included in the mash calculations, but if you check it, those ingredients will be included and the formulas will make more sense (assuming your ingredients should, in fact, be included in mash calcs).

    Here's an example similar to that last one posted. Without Mashed checked:


    And with:


    Could that be the problem? Or do you think there's something else going on?
     

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  10. Sjakkt

    Sjakkt New Member

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    Holy diver... that seems to do the trick - I haven't even noticed that checkbox before, but now I get the exact same numbers with custom fermentables as with the predefined ones :)

    Thanks Josh, can't believe I didn't try that before... :oops:

    Now I'm curious though: what are the numbers supposed to be if you DON'T check it - I mean the gravity goes through the roof..? I'm not sure I understand why the gravity is a lot higher until mashed is checked..?

    Anyways though, the important thing is that it works, thanks again!
     
  11. Josh (Brewer's Friend)

    Josh (Brewer's Friend) Administrator
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    Awesome! Glad to hear that helped! Yea, it's a little confusing, but the idea is that anything that's not Mashed is assumed to be added after the mash phase. This has two implications:
    1. The PPG number of a non-mashed ingredient isn't adjusted for mash efficiency. So this results in the higher OG numbers since it's not scaled by efficiency
    2. Since the predicted pre-boil values are based on the non-mashed ingredients, when we enter an actual value that's included those ingredients, it results in a calculated efficiency that's crazy high.

    Thanks again for the patience on this :)
     
  12. Serge Marx

    Serge Marx New Member

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    Ahhh!

    Cheers Josh, looks like we have a solution. Not intuitive though (but makes sense in how you're having to approach it), so maybe a note about this on the adding custom fermentables inventory page is a good idea.

    Thanks again - and just in time :)
     
  13. Ozarks Mountain Brew

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    maybe a good idea to have the check box selected my default
     
  14. Josh (Brewer's Friend)

    Josh (Brewer's Friend) Administrator
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    Hmm, yea that might be a good change. I'm wondering if the default behavior should be different based on recipe type though, e.g. All-Grain, Partial Mash, Extract. I'd think for Extract we may want to keep it off by default but otherwise I think most custom fermentables should probably be mashed by default. Or too confusing to have different behavior?
     
  15. Ozarks Mountain Brew

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    yes instead of defaulting it in the database, do an if statement based on what type of brew they are doing select on everything but extract
     
  16. Josh (Brewer's Friend)

    Josh (Brewer's Friend) Administrator
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    Yea, that's what I was thinking too - great, I'll work on that soon. Thanks for the input guys!
     
  17. bilhelm96

    bilhelm96 Member

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    Seems like a weird choice. Shouldn't pre-boil values be based on everything but late additions? In a Partial Mash situation or if I added sugar while the wort is coming up to a boil (which changes the volume) I would want the calculations to include the items in at the start of the boil.
     
  18. Josh (Brewer's Friend)

    Josh (Brewer's Friend) Administrator
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    Sorry, let me clarify. What I'm saying is that pre-boil efficiencies are high when ingredients that are, in fact, added in the mash, are marked as non-mashed. So in reality the pre-boil gravity is way higher than what's calculated (since those ingredients are excluded). So the actual pre-boil gravity compared to the calculated gravity results in an efficiency that's much higher than it should be.

    If adding sugars, etc. during the boil then those should increase the gravity after the boil, in which case marking them as non-mashed should result in accurate efficiencies.

    Does that make sense or am I not following what you're saying?
     
  19. bilhelm96

    bilhelm96 Member

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    I don't think you are following. I would think anything that goes in before the boil timer starts would be included in the pre-boil gravity reading. This would include anything included in the mash and other fermentables not marked as "late addition" Anything that is added after the boil timer starts doesn't get included in the gravity and should be checked as a late addition. The way you described it seems like only mashed items count toward pre-boil gravity.
     
  20. Ozarks Mountain Brew

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    maybe then a good idea would be a caption that explains things when you add a custom fermentable. at least that way they stop and look at the option
     

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