Refractometer Correction Spreadsheet

Nosybear

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Until the programmers can implement refractometer-based fermentation tracking, I'm adding a spreadsheet I developed to measure and track gravity using the refractometer during fermentation. You enter the reading in SG, it converts it to Brix, does the refractometer conversion then gives the value in SG. It also graphs the fermentation. Dang it, the file won't let me upload an xls! Any help from the admins?
 
if you have office 2016 you can export to a pdf file, even if you don't you can download an app that will
 
Looking forward to it.
Have you done actual side by side comps?
 
I got a refractometer specifically so I could track things on the pre-boil side but found it to be such a pain in the butt that I don't want to use it and have reverted to ignoring pre-boil and tracking efficiency, etc. by adjusting numbers to match the more reliable post-boil gravity readings.
It would be nice to have an easy way to use the refractometer and be able to trust the readings.;)
 
if you have office 2016 you can export to a pdf file, even if you don't you can download an app that will
It won't work as a .pdf, the formulas are eliminated. What I could do is to rename it to an "accepted" format and upload it with the instructions to rename it to Excel.
Looking forward to it.
Have you done actual side by side comps?
Yes, with finished gravity, it is accurate to 1 point (.001) SG. That's better accuracy than I can measure with my normal hydrometer, as accurate as I can get with my finishing hydrometer.
I got a refractometer specifically so I could track things on the pre-boil side but found it to be such a pain in the butt that I don't want to use it and have reverted to ignoring pre-boil and tracking efficiency, etc. by adjusting numbers to match the more reliable post-boil gravity readings.
It would be nice to have an easy way to use the refractometer and be able to trust the readings.;)
And yes, it is! No more guessing when to start diacetyl rests, no more guessing when things are done or when to add late syrups.... And the sample sizes are tiny! I filter out the trub from a couple drops of beer, measure, and don't even notice the losses over the entire batch. I've chatted back and forth with Yooper and she says it's an interesting addition to BF, no indication of when....
 
I got a refractometer specifically so I could track things on the pre-boil side but found it to be such a pain in the butt that I don't want to use it and have reverted to ignoring pre-boil and tracking efficiency, etc. by adjusting numbers to match the more reliable post-boil gravity readings.
It would be nice to have an easy way to use the refractometer and be able to trust the readings.;)
Just for reference, the refractometer is accurate pre-boil. It's when fermentation starts that the readings become distorted because of alcohol's higher refractive index.
 
Sweet. I look forward to checking this out. Thanks for sharing.
 
Just for reference, the refractometer is accurate pre-boil.
I don't find that to be the case. The last brew I tested with the refractometer read 1.045 pre-boil with all the runnings in the pot - 7.5 gallons. Dilution/Boil-off calculator shows that my post boil volume of 5.375 should be 1.063. It was 1.049. By using the efficiency percentage that makes the OG match the reading (86%), the calculator says that the pre-boil gravity should be 1.038
 
I don't find that to be the case. The last brew I tested with the refractometer read 1.045 pre-boil with all the runnings in the pot - 7.5 gallons. Dilution/Boil-off calculator shows that my post boil volume of 5.375 should be 1.063. It was 1.049. By using the efficiency percentage that makes the OG match the reading (86%), the calculator says that the pre-boil gravity should be 1.038
I'd check the refractometer - mine always agrees with the hydrometer. Given the small sample size, you may have had a drop or two of water in your dropper or whatever you used to transfer the sample to the refractometer's stage. You're right, your readings don't make sense. I'm not sure why - my readings agree initially and using the correction, throughout fermentation.
 
Make sure you test your refactometer with distilled water to make sure it reads 0
 
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Make sure you test your refactometer with distilled water to make sure it reads 0
Did...I'll try mixing some sugar water to similar gravity and see what it does. Wort color and particulate can throw it off, so by using a wort correction factor (still not certain how to nail that down) I can get to a proper reading. I may be able to adjust to it one way or another.
 
Did...I'll try mixing some sugar water to similar gravity and see what it does. Wort color and particulate can throw it off, so by using a wort correction factor (still not certain how to nail that down) I can get to a proper reading. I may be able to adjust to it one way or another.
The particulates give you a "fuzzy" line, make it harder to read. I filter my samples through coffee filter material to get the worst of the particles out of it. As far as the wort correction factor goes, if your refractometer reads in SG, you won't need it - it's already been applied. If you read Brix or Plato, you will need the correction factor, generally about 1.04.
 
this sounds like a nice tool to have.

can you upload to google docs and send a link?
 
As far as the wort correction factor goes, if your refractometer reads in SG, you won't need it - it's already been applied.

Interesting. I did not know this. If you have both is there an advantage to reading brix?
 
Not with my spreadsheet. Brix/Plato refer to the percentage of dissolved sugars using sucrose as a basis. In the initial formulas for converting refractometer readings into useful SG's, I had to convert to Brix but there's no real advantage.

I've had some trouble uploading the spreadsheet but I've sent it off to OMB - he thinks he can get it posted here.
 
Beer Refractometer Correction Fermentation Tracker.xlsx Download
 

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And if you want to nail the Wort Correction Factor down, take a wort sample and measure it with a precision hydrometer and the refractometer. Here are the BF instructions:

https://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/
I've checked out that page...it's useful info. Thanks. Even when I've used a hydrometer, I've consistently gotten higher pre-boil readings than what would make sense. I've tried a lot of things, but initial readings (in real time when it's helpful information to have) are always wonky. I may be missing something, but I manage to make good beer despite not having access to accurate pre-boil readings so I don't stress too much about it. ;)
 
Just for reference, the refractometer is accurate pre-boil. It's when fermentation starts that the readings become distorted because of alcohol's higher refractive index.
Great Tool.
my refractometer measures Brix directly. can i just typ in the Brix values?
 
Great Tool.
my refractometer measures Brix directly. can i just typ in the Brix values?
I didn't set it up that way - but you can modify it to take out the Brix conversion in column E and enter the data directly there. You'll have to know your refractometer's wort conversion factor - measure a few worts with both a refractometer and a hydrometer before pitching, the ratio is the correction factor.
 

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