BRIX to %water in honey

[Athorn]

Hi. I am new to beekeeping. Last year was my first. What a year! Does anyone know of or have a comparison chart for BRIX to %water content in honey. On a refractometer measuring BRIX only, the presumed wisdom is to subtract the BRIX reading from 100. eg 100-82 BRIX = 18 % water in honey. However honey is not just sucrose as the BRIX system is calibrated for so there should be a correction value. Thats the chart i,m looking for. It may be that the 18% in that example is accurate enough for general use but if the error is more than 1% then it could be the difference between "good" honey and "bad" honey.

 

[Black Comb]

Have a read through this thread
http://www.beekeepingforum.co.uk/showthread.php?t=2232&highlight=refractometer&page=2

 

[Easy Beesy]

Sorry BC. It didn't really help. I could use our lab one but its BRIX and I don't know if it is suitable.

 

[alanf]

The refractometers sold for honey have a scale for a typical mix of sugars in the 58 to 90% range. The actual refraction will vary with the mix but they are 'good enough' to work out when you're well in the safe range 18 or 19% or fermentation territory at 23 or 24% water. Not aware of any standards based table, but there are illustrations of the 3 scales side by side as they appear on some instruments, even on the eBay listings. The illustrations look to be a fair reflection of what's visible through the eyepiece. Close enough for a working approximation anyway.

 

[Hombre]

Jim Fischer over on BeeSource post '4 in the thread gives you both a link to a scale to do an eyeball conversion.

1 degree Brix is 1% sugar at 20 degrees C (68F.

I guess we are really interested in a sub scale that will range from 75% to 87% sugar or thereabouts? The balance between that and 100% being the water content.

A honey refractometer is merely one with a display scale that covers the area of interest, rather than having a more general purpose scale which would be more difficult to read do to the size.

Pretty much what AlanF has already said.

 

[VEG]

why not just buy one that is for honey and gives the moisture content in a very easy to read scale without all the conversion tables and so on?

 

[Black Comb]

Yes. My £16 one off ebaydoesthe job. Calibrated with olive oil.
You can check a few samples from capped honey which is usually 17 or 18% and you know it is working ok.

 

[Athorn]

Thanks to everyone for all your help. I have found a couple of conversion tables on the internet. One from refractive index to BRIX and another from refractive index to %water in honey. From those i have constructed a conversion table between BRIX and %water in honey. The reason i have had to go this way is i saw a digital refractometer in the Thornes catalogue at £225.00. I then tracked one down from Conrad-uk.com for £163.99 inc vat but plus postage. I ordered one, then saw on the internet that the 100-brix was not exactly correct for %water in honey. It is -%1.6 over almost the whole range. That means if i read 81 brix on a refractometer the real %water in honey is not for eg 100-81= 19, but actually 19-1.6 = 17.4% water in honey. Thanks again, hope this is of help to others.

 

[VEG]

My refractometer was under £20 and works a treat

 

[alanf]

The reason i have had to go this way is i saw a digital refractometer in the Thornes catalogue at £225.00. I then tracked one down from Conrad-uk.com for £163.99 inc vat but plus postage. I ordered one, then saw on the internet that the 100-brix was not exactly correct for %water in honey. It is -%1.6 over almost the whole range

The refraction will vary by honey composition. If you wanted real accuracy on water percentage you would need to know the percentages of fructose, glucose and sucrose. That would add additional correction factors. And those factors would vary, just as the water content varies. Between supers, between frames, even across frames.

The instruments under 20 quid on eBay are accurate enough for the purpose and similar to the one th0rnes sell for 80. Save your cash.