formula for abv from refractometer readings

Discussion in 'General Home Brew Equipment Discussion' started by bobukbrewer, Jan 12, 2019.

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  1. Jan 12, 2019 #1

    bobukbrewer

    bobukbrewer

    bobukbrewer

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    I have two formulas, one is =IF(F7=0, (0.01/0.8192)*((C7/$E$3)-(0.1808*(C7/$E$3) + 0.8192*(668.72*H7 - 463.37 - 205.347*H7^2)))/(2.0665 - 0.010665*(C7/$E$3)), (0.01/0.8192)*((C7/$E$3)-(0.1808*(C7/$E$3) + 0.8192*(668.72*F7 - 463.37 - 205.347*F7^2)))/(2.0665 - 0.010665*(C7/$E$3))) where C7 and D7 are OG and FG in BRIX, this gives 2.52 abv for my last brew with OG 9 and FG 5.9

    the other formula is =B36*B37/0.791 giving 2.74 abv with B35 being =((C7/$E$3)/(258.6-(((C7/$E$3)/258.2)*227.1))+1)

    e3 is wort correction factor 1.04
    b36 is =-0.002349*C7+0.006276*D7+1
    b37 is abw =0.67062*C7-0.66091*D7

    which do you consider is most accurate
    (I wish to use refractometer only so no plugs for hydrometers please
     
  2. Jan 12, 2019 #2

    Bigcol49

    Bigcol49

    Bigcol49

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    Hi!
    The problem is findingthe wort corection factor oyour refractometer.
     
  3. Jan 12, 2019 #3

    bobukbrewer

    bobukbrewer

    bobukbrewer

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    I am happy with 1.04
     

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