Refractometer calibration issues

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kennyconley0269

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Does anyone law have major accuracy issues with refractometers? I have tried multiple meters from different manufacturers and I can’t get them to work right. If I calibrate with distilled water per the instructions all my readings come out low. If I calibrate with a hydrometer reading then it will be accurate to that reading but the farther I deviate from that SG the more inaccurate it is.

Any advice on this would be appreciated. It would be great if I could rely on Refractometer readings and not have to pull a 100ml sample every time I want to check my SG.

Thanks
 

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I have tried multiple meters from different manufacturers and I can’t get them to work right
Dont' take this the wrong way, but off the top that probably means it's a problem with the method, not the equipment.

all my readings come out low
Compared to what? A hydrometer?

Thoughts: 1) Your hydrometer could be off. 2) Your sample going into your refractometer may need some help. Maybe what you are measuring isn't totally stirred up and mixed. Maybe it's too hot. Maybe it has a bunch of haze and particulates in it that need a chance to settle.

When I pull a thoroughly mixed wort sample, let it rest a few minutes (10), and then take a reading it matches my hydrometer basically perfectly.

Also FYI it's not for measuring anything with alcohol in it, only prior to fermentation. If you measure "beer" you should either use a hydrometer or at least refer to the charts with the corrections.
 

bracconiere

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i'm not sure if this matters, but how precise are you trying to be? i can only guess between 1 BRIX on mine...which is multiplied by 4 to get SG i think.....
 

DBhomebrew

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1 - Disregard the SG (1.xxx) scale.

2 - Read in Brix and use a refractometer calculator to find your actual SG. Part I pre-pitch. Part II post-pitch. 1.04 is a good default wort correction factor (WCF).


3 - Calibrate to distilled water.

4 - Be sure your wort is well mixed before pulling a sample.

5 - There are other best practices, but that's a good start.
 
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kennyconley0269

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Thanks for the tips guys. I bought a Refractometer after seeing videos of commercial breweries pulling wort right out of the mash and getting their readings right away. That is apparently not how it works. If the sample has to settle out and reach room temp then I see no benefit to using one versus a hydrometer. Especially considering the whole issue of wort correction factors, and not being reliable for FG readings only OG readings. Seems to be not a very useful instrument.
 

DBhomebrew

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To each their own. But a few comments...

Thanks for the tips guys. I bought a Refractometer after seeing videos of commercial breweries pulling wort right out of the mash and getting their readings right away. That is apparently not how it works. That's actually totally fine. Pre-fermentation you can use the SG scale for rough work. Some brewers find their refractometer's SG scales to be very accurate in the normal range.  Ifthe sample has to settle out and reach room temp then I see no benefit to using one versus a hydrometer. Same with the hydrometer, but a smaller sample cools faster. Especially considering the whole issue of wort correction factors, Not a big deal. Ignoring it completely doesn't skew the gravity or ABV very much. and not being reliable for FG readings only OG readings. Totally reliable when used with best practices (same as a hydrometer) and a simple plug and play calculator. Seems to be not a very useful instrument. I find mine to be very useful and rarely resort to the more cumbersome hydrometer.
 

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I love my refractometer as well, but yeah you need to do a little work. I still find it to be less work. Hydrometer needs a cool sample as well but a whole lot more of it which takes logner to cool down. And so on.

I keep a shot glass in the refrigerator near where I brew, and a little wort sample goes in there. I get a reading within 5 minutes. Not perfect, but far better.

I've also found over time that I don't need the reading for my current batch, What is done is done. I keep that reading more for planning the next batch, so I can realize - "oh, that extra grain dropped my efficiency from 80% to 75%" and then I can plan accordingly. Being a few points of gravity off my target - it ain't no thing. I no longer check gravity planning to react right away. This is somethign that does take time and routine though.
 

youngdh

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Thanks for the tips guys. I bought a Refractometer after seeing videos of commercial breweries pulling wort right out of the mash and getting their readings right away. That is apparently not how it works. If the sample has to settle out and reach room temp then I see no benefit to using one versus a hydrometer. Especially considering the whole issue of wort correction factors, and not being reliable for FG readings only OG readings. Seems to be not a very useful instrument.
I do 2.5G batches and using a refractometer waste far less wort than the hydrometer. I’ve checked my refractometer against my hydrometer at end of boil and it is spot on. You do need to give the couple of drops on the refractometer about 30s to approach room temp. When measuring for FG be sure to use a correction tool to correct for alcohol. I use the one on brewersfriend.com. After correction my refractometer agrees with my hydrometer. If you’re refractometer is still way off it’s possible you have a bad unit.
 
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