BRIX Calibration

[ramloese]

i bought a refractometer, but it only has Brix. I bought some calibration fluid that says 35. But when applying it, what should I set the BRIX to?

 

[Smellyglove]

Why not use water and set it to 0?

 

[ramloese]

Water only provides a higher limit, not a lower limit and thus is imprecise

 

[doug293cz]

What is the calibrating solution you bought? You can zero with water, and the take a measurement on your calibrating solution. If it reads near 35, then things are as expected, and you probably have a calibrating solution that is in fact 35 Brix. If it reads way off, then you have no idea what your calibration solution actually is.

You can make your own calibration solutions if you have an accurate scale. 25 g of table sugar (sucrose) in 225 g of water will give you about a cup of 10 Brix solution. 50 g in 200 g water will give you a 20 Brix solution. 75 g in 175 g of water will give you a 30 Brix solution.

Brew on

 

[ramloese]

What is the calibrating solution you bought? You can zero with water, and the take a measurement on your calibrating solution. If it reads near 35, then things are as expected, and you probably have a calibrating solution that is in fact 35 Brix. If it reads way off, then you have no idea what your calibration solution actually is.

You can make your own calibration solutions if you have an accurate scale. 25 g of table sugar (sucrose) in 225 g of water will give you about a cup of 10 Brix solution. 50 g in 200 g water will give you a 20 Brix solution. 75 g in 175 g of water will give you a 30 Brix solution.

Brew on

My issue is that there is no such thing as 35 BRIX on my scale. It's in percentage.

https://www.amazon.com/dp/B0053DSWJA/?tag=skimlinks_replacement-20

 

[doug293cz]

My issue is that there is no such thing as 35 BRIX on my scale. It's in percentage.

https://www.amazon.com/dp/B0053DSWJA/?tag=skimlinks_replacement-20

That stuff is for calibrating refractometers used to test saltwater fish tanks. If you got an aquarium refractometer, you got the wrong thing.

You could use the 0, 10, 20, and 30 Brix solutions to create a translation table for a saltwater refractometer, but that would be a real PITA. Especially when you can get a BRIX refractometer for about $20. Don't bother with the dual scale ones that also have an SG scale, cause on most of those the SG scale is borked (20 Brix is 1.083 SG, but on the dual scale refracts it usually reads about 1.087- 1.088.)

Brew on

 

[ramloese]

That stuff is for calibrating refractometers used to test saltwater fish tanks. If you got an aquarium refractometer, you got the wrong thing.

You could use the 0, 10, 20, and 30 Brix solutions to create a translation table for a saltwater refractometer, but that would be a real PITA. Especially when you can get a BRIX refractometer for about $20. Don't bother with the dual scale ones that also have an SG scale, cause on most of those the SG scale is borked (20 Brix is 1.083 SG, but on the dual scale refracts it usually reads about 1.087- 1.088.)

Brew on

This is my refractometer:
https://www.amazon.com/gp/product/B008562GD0/?tag=skimlinks_replacement-20

Im certain it will work for wort.

I have yet to hear anyone with the answer to what 35 ppt is equivalent to in BRIX

 

[doug293cz]

That refractometer is just fine.

35 ppt is 35 parts per thousand, which is the same as 3.5% (percent is parts per hundred.) I have no idea why they don't just say 3.5%, since "ppt" is a very seldomly used unit.

Brew on

 

[ramloese]

Thank you!

 

[Smellyglove]

Water only provides a higher limit, not a lower limit and thus is imprecise

I didn't understand this, can you please explain?

 

[balrog]

You can make your own calibration solutions if you have an accurate scale. 25 g of table sugar (sucrose) in 225 g of water will give you about a cup of 10 Brix solution. 50 g in 200 g water will give you a 20 Brix solution. 75 g in 175 g of water will give you a 30 Brix solution.

Oooooh, I like this idea. So if I put 35g sugar in 225g water, getting ~13.5% ==> 1.055
Add 25g more water to that, changes solution to 12.3% ==> 1.050
Add 175g more water to that, changes solution to 7.6% ==> 1.030
Add 225g more water to that, changes solution to 5.1% ==> 1.020

And I can see how both my Ref and Hydr do at each step of the way?

 

[doug293cz]

Yep, but any solution you lose during measurement will add error to subsequent solution concentrations. Even your math checks out. To avoid having to deal with trying to compensate for lost solution, I would just make up separate standard solutions, rather than doing sequential dilutions.

Brew on

 

[balrog]

Even your math checks out.

I learned a trick in graduate school (Physics)—do math before drinking.

 

[Qhrumphf]

Brix is by definition %w/w sucrose in water, so that's why that works.

Your calibration solution probably isn't designed for a Brix refractometer. That particular scale may not even register on your device. There are different refractometers built for different things. Glycol solution can be read with a refractometer as well- but that style refractometer reads freezing point of the glycol solution.

I don't think your calibration solution will work here. You're better served making a sucrose solution as above.

And then the best thing you can do is to measure wort of various compositions of known gravities with both an accurate hydrometer and your refractometer, and determine any corrective index needed. Wort isn't just sucrose afterall, and not only does maltose not refract identical to sucrose (similar but not the same), your grain bill and mash schedule can vary your sugar composition pretty significantly. I've been lucky that all the refractometers I've used have been close enough to a 1.00 index to take at face value, but that's not the norm.

As an acquaintance of mine put it once: "refractometers lie". He won't use em. I'd rather use em when practical but know their limitations.

 

[Qhrumphf]

That refractometer is just fine.

35 ppt is 35 parts per thousand, which is the same as 3.5% (percent is parts per hundred.) I have no idea why they don't just say 3.5%, since "ppt" is a very seldomly used unit.

Brew on

I though ppt could also mean parts per trillion? (Edit: some searching says according to convention parts per trillion is normal for ppt, parts per thousand should be spelled out as such to avoid confusion)

I prefer mg/l and other associated notations for this reason.

 

[doug293cz]

I though ppt could also mean parts per trillion? (Edit: some searching says according to convention parts per trillion is normal for ppt, parts per thousand should be spelled out as such to avoid confusion)

I prefer mg/l and other associated notations for this reason.

But you're not going to read 35 parts per trillion of anything with a refractometer. So for that solution parts per thousand is the only thing that makes sense.

Found this at: https://en.wikipedia.org/wiki/Saline_water

Saline water (more commonly known as salt water) is water that contains a significant concentration of dissolved salts (mainly NaCl). The salt concentration is usually expressed in parts per thousand (permille, ‰) or parts per million (ppm).​

Brew on

 

[Qhrumphf]

But you're not going to read 35 parts per trillion of anything with a refractometer. So for that solution parts per thousand is the only thing that makes sense.

Found this at: https://en.wikipedia.org/wiki/Saline_water

Saline water (more commonly known as salt water) is water that contains a significant concentration of dissolved salts (mainly NaCl). The salt concentration is usually expressed in parts per thousand (permille, ‰) or parts per million (ppm).​

Brew on

I suppose contextually that does make sense. Still an ambiguous notation.

Cheers.