my hydrometer and refractometer disagree

I checked both with water and they both seem to be calibrated. My refractometer says ~12.5 - 13 and the hydro says 1.042 in 80° wort. Even with the temp adjustment its only 1.044. Thats a 5 to 7 point difference. Which should i trust?

Guess ill never know.

What do they measure in room temp distilled water?

Mine did too, which led me to actually check my hydrometer in distilled water. With temp correction my hydrometer read +4 points and confirmed that my refractometer was correct. This explained why my gravities were on the high side...by four points!

If you're measuring a solution with alcohol present in it, then neither will be accurate anyway. There are correction formulas on Braukaiser.com for that though.

basilchef said:

I checked both with water and they both seem to be calibrated. My refractometer says ~12.5 - 13 and the hydro says 1.042 in 80° wort. Even with the temp adjustment its only 1.044. Thats a 5 to 7 point difference. Which should i trust?

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12.5 - 13 is a big difference! My refractometer has lines at 2 "degrees" just like a thermometer. 12.8 and 13 are pretty close even, but you can tell them apart. Mine has a big line at 12 and 13, but small lines at every .2. If you're halfway between 12 and 13, check to see which line you're closer to.

I'd use distilled water, and check again to make sure that the refractometer is at 0 with distilled water.

If the hydrometer is 1.000 in distilled water, I'd trust that.

Thanks everyone. Ill check soon

I have the same problem. I have two hydrometers and they both read the same, my refractometer was way off and was calibrated with RO water. It constantly reads about 1.012 higher then my hydrometers. I bought a new refractometer and it reads about 1.008 higher and it was calibrated with RO water also.

Monster Mash said:

I have the same problem. I have two hydrometers and they both read the same, my refractometer was way off and was calibrated with RO water. It constantly reads about 1.012 higher then my hydrometers. I bought a new refractometer and it reads about 1.008 higher and it was calibrated with RO water also.

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Have you calculated the refractometer brix to hydrometer adjustment factor? My brix correction factor is 1.02681. If you can calibrate your refractometer with your hydrometer, and find the correction factor, and then compare all readings by using that correction factor, you should be all set!

My refractometer not only doesn't agree with my hydrometer, but I can take 5 samples and have a range of error of well over 1.010 in total. I don't know if mine sucks, if what's being sold to homebrewers sucks, or if it's just not all that reliable, but it's kinda hard to trust it.