Refractometer on the fritz?

[leboeuf]

Hey guys, has anyone had their refractometer read wayyyyy too high of OG for their brew? I made an amber with 10.5 lbs of grain on Saturday and the pre-boil OG was reading at 1.070? The tool is borrowed and I can't seem to find my my hydrometer anywhere. It's odd, the thing reads in specific gravity not in brix? I've never really used a refractometer for beer, my friend had it around for aquarium salinity measurements.

Thanks,
Tom

 

[GilaMinumBeer]

I know that not all refractometers are the same and wonder if a salinity refractometer uses the same refractive indices as for sugars. That may be the problem.

Otherwise, have you tried looking at distilled water? The reading should be Zero. If it is not, then it's in need of adjustment. There should be a small screw, maybe even a small knob, to adjust the calibration.

 

[leboeuf]

It is calibrated correctly. I would think sugar and salt dilution would cause the same change to index of refraction. Hmmmm.... I'll look into this a bit more. I suppose I don't know if a gram of dissolved sugar causes the same volumetric change as a gram of dissolved salt?

I thought all refractometers on the market were intended for measuring salinity?

 

[leboeuf]

I just talked to the guy that loaned me the refractometer. Apparently there is a different type of unit for measuring sugar content. So, I'm off to find my hydrometer to work out a conversion for this thing...