Refractometer Calculator

Discussion in 'General Brewing Discussions' started by CoachHirsch, Mar 19, 2017.

  1. CoachHirsch

    CoachHirsch New Member

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  2. HighVoltageMan!

    HighVoltageMan! Well-Known Member

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    I use my refractometer every time I brew and I find it to be a useful tool. But if there is any alcohol in the beer/wort I'm measure gravity on, I go old school with a hydrometer. I have never been able to get consistent, reliable results when there is any alcohol involved, calculator or not.

    The conversion between brix and gravity is easy. 12 brix multiplied by 4 equals 1.048. So either multiply or divide by 4 to convert between the two.

    I use the refractometer for getting starter gravity correct, mash and boil gravity. It's changed the way I manage my boil, I don't boil for volume anymore, only for gravity.
     
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  3. Nosybear

    Nosybear Well-Known Member

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    Ditto here. And a sample costs me a few drops of beer, it cools to measurement temperature rapidly.... Far superior to a hydrometer as long as there's been no fermentation.
     
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  4. Myndflyte

    Myndflyte Active Member

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  5. Nosybear

    Nosybear Well-Known Member

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    I generally only take two gravity measurements: Pre-fermentation at pitch temperature and post-fermentation. I'm tasting the sample post-fermentation sample so it's a justified loss of beer. To me it's not worth the risk of contamination and oxidation to open the fermentor several times just to take gravity readings so I leave it alone.
     
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  6. CoachHirsch

    CoachHirsch New Member

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    Thanks. I'll check it out. Just seeing different calculations for FG and trying to find the most accurate method which is also simple.
     
  7. Brewer #102416

    Brewer #102416 New Member

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    I'm a little confused about the calculator as if you enter, say 12 plato beer with an FG of 2, it shows -2plato for FG correction.
     
  8. Nosybear

    Nosybear Well-Known Member

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    I tested them on a batch of Helles, using my refractometer to monitor fermentation. I took two checks of the beer against the hydrometer, a finishing hydrometer with nice, wide graduations in one degree SG increments. The difference between the readings using the calculations recently published in Zymurgy Magazine was less than one point. One area that was interesting was finding the wort correction factor: My hydrometer reads both SG and Brix but I was using a conversion table. Apparently the table had the wort correction factor already applied: I got the same results using a wort correction factor of 1 rather than the often cited 1.04. Next time I'll try using the Brix values in the hydrometer and the conversion factor and see if I get the same results.

    I will say this: Being able to monitor the fermentation using only a couple drops of wort is very nice. Takes a little math but I'll set up a spreadsheet to do it the next time. If the conversion formula continues to be reliable, I'll repeat it here.
     
  9. Nosybear

    Nosybear Well-Known Member

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    That needs to be the Brix final gravity on your refractometer. Because alcohol has a higher index of refraction, it'll give a higher reading than a pure sugar solution (the basis of Brix). When I put the parameters in for my Helles, it comes out within a couple points of the same. Next brew I'll determine the WRI for my refractometer by measuring the OG both by hydrometer and refractometer. After doing this a couple times, I'll apply the statistics and see what value I should use across a range of OGs. It's a bit of experimentation but worth it if I can throw the test jar away (not really, I'll still do official OG and FG with it).
     
  10. BoomerBrian

    BoomerBrian Active Member

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  11. Nosybear

    Nosybear Well-Known Member

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    It's likely the same math. Difference is finding the wort correction factor for your refractometer.
     
  12. BoomerBrian

    BoomerBrian Active Member

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    Yes. If I remember their default correction factor was closer to mine. I need to properly find my correction factor.
     

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