Mash temp vs FG

Discussion in 'Recipe Editor' started by Yves de Champlain, Mar 1, 2017.

  1. Yves de Champlain

    Yves de Champlain New Member

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    Hi

    I just found something weird with mash temp vs FG. Maybe this is OK, but ...

    I made a quite hot mash (71 °C instead of 67 °C) so I adjusted it and got the same FG (1.015), which is weird. However, as the mash went on I found it was nearer 70 °C so I made the adjustment again and then got a much higher FG (1.018) which is what I expected in the first place. I made screenshots.

    Is it alright for the FG to go down at 71 °C ?

    Thanks !

    Capture d'écran 2017-03-01 12.00.06.png Capture d'écran 2017-03-01 12.00.20.png
     
  2. Trialben

    Trialben Well-Known Member

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    You'd expect it to go the other way?:rolleyes: The hotter the mash temp the more less convertible sugars - dextrin's and the cooler the mash plus longer mash time should equal more fermentable wort maltose in theory o_O.
     
  3. Yves de Champlain

    Yves de Champlain New Member

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    Right ! So why more fermentable sugars at 71 °C than at 70 °C ??? That is the question !
     
  4. Ozarks Mountain Brew

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    theirs a variable your missing, the yeast attenuation % ,its a factor in the final gravity
     
  5. Yves de Champlain

    Yves de Champlain New Member

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    I'll try to say it simpler : With no change in yeast attenuation or anything else, how come 71 °C predicts more attenuation than 70 °C ?
     
  6. Trialben

    Trialben Well-Known Member

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    #6 Trialben, Mar 2, 2017
    Last edited: Mar 2, 2017
    Yea I'm picking up what your putting down I think it's a glitch in the calculator ;).mimwould expect the opposite to happen and the wort to become less fermentable through higher mash temp. Maybe a difference of 1c but let's say a mash temp of 65c compared to 68c there should definitely be a noticeable difference in attenuation. Brulosopher has done a exbeerment on this btw one mash low and the other high and weather people could taste the difference.

    I just mucked around with the mash temp on one of my recipes 65c gives me the best attenuation 61c lower attenuation then 65o_O but when going up in temp from 65 to 68 it makes sense but then 70c + it goes outta whack.
     
  7. Brew Cat

    Brew Cat Active Member

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    I never put much faith in those online calculators except for predicting OG. To many variables with the yeast attenuation. The calculator uses an average and it's really hard to predict what I get. Although I have started mashing 3 or for degrees warmer to keep my FG up and that's what happens. The OG stays them same and the FG ends higher
     
  8. Anthony G Milner

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    I think Brewcat is right there, I tend to mash cooler, 63 to 65 max (c)
    and I get a different result than the calculator, my last one (Hulme Pale Ale)
    started at 1050 and the Fg was1007 about 4 points better than the calculator
    As long as the beer tastes good - no problem!
    Cheers
     
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  9. Yves de Champlain

    Yves de Champlain New Member

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    Indeed, fermentation temperature is often a much more important factor, and I usually get what I get with FG. I just find these numbers weird.
     
  10. Yooper

    Yooper Administrator
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    I do, too. I will check into this.
     
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  11. Yves de Champlain

    Yves de Champlain New Member

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    In the end, I got very bad results everywhere, which can only be IMHO the results of a too high mash temperature :

    1.052 OG with 7 Kg of grains for a magnificent 60% Kettle efficiency
    1.020 FG with S-04 at 21 °C for a very shy 66% attenuation

    So maybe instead of trying to adjust the results, BF should just send an alert: "What the hell are you doing mashing at that temperature ??? Don't stand there gaping and pour some cold water in there !" :p

    The good news is the beer is good, just not what I expected !
     
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  12. Trialben

    Trialben Well-Known Member

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    So you ended up mashing at 70-71c :eek: sweet dreams my friend ha ha. Sorry that's rude but you know the calculator is wrong in that scenario lol. Now what's your head retention like on that brew? I've been reading,plenty of info on mash out of 71 ish c for 40-50 mins to aid in head stability compound ??
     
  13. Yves de Champlain

    Yves de Champlain New Member

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    Well, my English's not good enough to understand how that should be rude !

    Anyway I can't say much more right now because the beer is sitting in secondary awaiting an empty keg, but I'll give my impressions when the time comes.
     
  14. jeffpn

    jeffpn Well-Known Member

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    I've got 3 ales waiting on kegs, but I've got 2 kegs waiting on lagers!
     
  15. Yves de Champlain

    Yves de Champlain New Member

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    "Rollin' on the river ..." :cool:
     

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