• Please visit and share your knowledge at our sister communities:
  • If you have not, please join our official Homebrewing Facebook Group!

    Homebrewing Facebook Group

Fuzzy Refractometer

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

RDWHAHB

Well-Known Member
Joined
Oct 9, 2009
Messages
846
Reaction score
20
Location
Denver
So I have a new refractometer. I measured my OG the other day, and it wasn't too fuzzy, but today I tried to take another reading. The "blue/white" line was crazy fuzzy. I didn't have bubbles. What can cause this?
Thanks, Jeff
 
I would say it's CO2. Maybe you can't see the bubbles but there is dissolved CO2 in there. There are other things though. The way a refractometer works is by measuring how the light is refracted through the substance. The light bends according to how much stuff is dissolved in the water. Yeast, alcohol, that stuff you spilled in there, dirty lens could all effect your reading. If there are solids or gasses mixed into the beer you will not get a clear reading. You should be able to make a pretty good guess. Try to find the middle. That should be your reading. Oh, and RDWHAHB.
 
Make sure the flap/cover is completely flush on the lens, to make sure that the depth of your liquid beneath is consistent. Also, the brighter the light shining into it (I find daylight to be by far the best), the clearer it will be.
 
I wondered about the yeast. Didn't even think about the CO2. That could be it. I'll try daylight. It seems to be hard to come by these days.
 
I had the same thing with a wheat beer I just kegged. Normally the line is nice and crisp. I assumed it could be a result of all the yeast in suspension. I estimated the reading and confirmed I was fairly close with a hydrometer prior to kegging.
 
Your refractometer may be out of focus. Turn the eye piece in or out to refocus. I need to do this each time I use mine, because I invariably turn the eyepiece when I clean the sample off and wipe it dry.
 
I have the same problem if I have a lot of break material in my sample. It puts the cover further away from the sample window. Sometimes putting a little pressure on the cover plate helps focus that line.
 
Back
Top