Final Gravity based on Mash Temp

Discussion in 'Brewer's Friend Announcements' started by Josh (Brewer's Friend), Mar 17, 2015.

  1. Josh (Brewer's Friend)

    Josh (Brewer's Friend) Administrator
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    One of the top requests we've received is to add smarter final gravity calculation on the recipe builder. And for good reason: nothing's more frustrating that planning a recipe to perfection and coming out with a different FG, hence ABV than you planned. Today we rolled out the first in a series of changes to make this calculation better.

    The recipe builder now takes mash temperature into account when calculating yeast attenuation, which in turn influences final gravity. To try it out, just visit the recipe builder:
    http://www.brewersfriend.com/homebrew/r ... alculator/

    Add some fermentables and then add a mash step in the 145 to 165 range. You'll notice that the FG calculation starts to adjust itself based on this temperature. Please experiment with it and let us know how it's doing. In the analysis we've done, we've found it to be much more accurate, but we want to hear how it's working for all of you.

    This change is only for the desktop version of the calculator currently, but we'll be rolling out similar updates to the mobile apps soon.

    Prost!
     
  2. Ozarks Mountain Brew

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    looks good on paper I guess will see in time. thanks
     
  3. James Vendel

    James Vendel New Member

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    Thanks for the notice, Josh. It seems the new feature affects editing saved recipes - edit a recipe with FG x and when the recipe re-calcs and displays it now shows FG y, presumably based on the mash temps stored with the original recipe.

    It created a little confusion for me initially. Perhaps I am not using the tool correctly, but the mash temps I stored with my recipes were actually my strike temperatures, not my targets. So when I edit a recipe now the first thing I have to do is to edit the mash temps to reflect target temp instead of strike temp in order to restore the original value for FG stored with the recipe. At least that is what I assume I need to do based on your description of the software change and the small amount of fiddling I've done so far. Does that sound right to you?

    Jim
     
  4. ManhattanProjectBrewing

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    Hey There,

    It appears the calculations do not take into account step programs. For instance: Protein rest at 122F then on to Sacc. @ 151F (From decoction) then to mashout @ 170F (From decoction)... I went from 6.09% to 3.79%.. Whoa. Is there a trick or other insight that may lead to accurate numbers? I have brewed this recipe before and hit numbers WITHOUT the new calculations. Maybe make this an option? Make it so we can toggle on/off and not leave it mandatory? Just my $0.02.... Cheers! Keep up the great work!

    Best,

    -JM
     
  5. Kevin The Stout

    Kevin The Stout New Member

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    There needs to be some way of over-riding this. Computers trying to be smart usually precedes a screw-up. I was wondering why the ABV calcs were way off on my Lagunitas IPA Clone and it seems this is why. My recipe follows that given by the Lagunitas brewer on CYBI. It uses a mash temp of 71.1degC but still gets about 75% attenuation.

    A sensible quick fix would be that if a custom attenuation is specified for the yeast then use that for the apparent attenuation rather than any guesstimates based on mash temperature.
     
  6. edwilson66

    edwilson66 New Member

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    Dear Josh, before this change I used to correct my attenuation on the "Yeast Custom attenuation". Now, using Safari from my IPAD, this is not happening anymore. The attenuation that appears on the FG is always based on the Mash temp, even in High mashing temperature of sacarification.

    Please, help me!!! I think the best way to achieve your attenuation is having both options, Yeast Custom Attenuation or Mash Temp, because of the equipment profile correlation. I like to use Yeast Custom Attenuation!

    Is this change only for desktop environment? Why am I facing this problem?

    Tks. Ed Lameira
     
  7. PZ

    PZ Member

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    Interesting idea, but I'm not sure the small adjustments are that useful. The speed the brewer mashes in can result in a different time span spent at a temperature that differs from the target mash temperature. Ditto with heat loss over the hour (or so) and whether a mash out is employed. I generally enter a custom attenuation as a target and based on experience take a stab at a mash temperature. I think in general terms of low (148-150) and high (155+) with medium somewhere in the middle. Luckily it's possible to make great beer in many different ways.
     

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