Noob question-refractometer vs. hydrometer

Discussion in 'Homebrewing' started by Kunkledude, Jul 23, 2016.

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  1. Kunkledude

    Kunkledude Initiate (0) Jan 10, 2016

    My appologies for being stupid.

    Getting ready to bottle today and measured my FG. I borrowed a digital refractometer from work to measure the OG and FG. I tested a sample before bottling with both devices. The refractometer: FG= 6.0 brix, hydrometer= 1.008.
    Which one do I use? The OG was 13.1brix, (1.054). I did not have the opportunity to measure the OG with a hydrometer. I did calibrate both units with deionized water.

    My gut tells me the hydrometer will be a more 'true' reading since it is physically sitting in the batch. Since I had a low OG which was way off the target, 1.070 vs. 1.054 the 6.0 reading may be more resonable.

    Thanks.
    Leo
     
  2. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    You need to use a calculator to convert refractometer readings to OG and FG. (The computations for each are different, and the FG calc is also dependent on the OG.) But it's easier than it sounds.

    Sean Terrill's is the best standalone calculator. BrewCipher uses Sean's formulas (slightly modified), inside of an integrated brewing spreadsheet.
     
  3. Kunkledude

    Kunkledude Initiate (0) Jan 10, 2016

    I have used Sean Terrill's calculator and its great. Even though the hydrometer does not have any bells and whistles, it seems it would be a truer indicator of the sp. gravity. The difference in ABV would be large considering the two values.
     
  4. Buck89

    Buck89 Grand Pooh-Bah (3,782) Feb 7, 2015 Tennessee
    Pooh-Bah Trader

    This does not seem way off to me. Using BrewCipher, 13.1 is approx 1.050 OG and 6 would be approx 1.010 FG.
     
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