Refractometer

[john langley]

Greetings;

Wondering if the 'fuzzy' refractometer line when trying to get a gravity reading is a function of the quality of the refractometer itself or the clarity of the liquid being measured ?

 

[Hoppy2bmerry]

Might be too much wort on the instrument, clean it and just use a small drop. Also did you focus?

 

[Robert65]

Cloudy beer with yeast in suspension will contribute. You can run your sample through a coffee filter to clear it up a bit.

 

[seilenos]

I can only speak to the refractometer that I have since it is the only one I ever used...

The underside of the flap that covers the sample end of the instrument is rough. I found that if I open the flap the whole way and put a few drops on it first to cover and "fill in" the roughness and then put a few drops on the end I almost always get a sharp line upon reading.

If I just put a few drops on the end and then flip the cover closed I get a fuzzy line that spans a few points.

My guess is that it has something to do with entrapped air on the underside of the flap.

 

[kh54s10]

For mine to read sharply I have to hold the flap down, gravity alone doesn't work.

 

[Broothru]

Cloudy beer with yeast in suspension will contribute. You can run your sample through a coffee filter to clear it up a bit.

Could the sample also need de-gassing? It seems that if I view a sample directly from an active fermentation without vigorously stirring and letting it settle for 30 minutes or so before putting it on the platen that the "line" is almost unreadable fuzzy.

Brooo Brother

 

[Robert65]

Could the sample also need de-gassing? It seems that if I view a sample directly from an active fermentation without vigorously stirring and letting it settle for 30 minutes or so before putting it on the platen that the "line" is almost unreadable fuzzy.

Brooo Brother

I find that a coffee filter is reasonably effective at degassing as well as separating particulates. Some more bubbles might form if left a while, I suppose. I use a digital refractometer now, but the principle is the same: drip through coffee filter onto refractometer stage, wait a minute for temperature to equalize, and read. Works for me.