Refractivitiy And Sg...wtf

[jeddog]

OK
Did my first AG which was a lager, I used a Refractometer for the first time make beer, the Lager Brix % was 9.0 (1.037) I have waited a 2 weeks and the Brix % was only down to 4.0 % (1.017) after checking for some days.

My problem is:
I checked this reading with my Hydrometer and it gave me a reading of SG1.004 much lower than what i expected. I did a comparison with both the Refract and the Hydro with distilled water at 20c and both gave me a reading on 0% -SG 0 ....WTF :blink:

any help would be much appropriated

 

[the_fuzz]

OK
Did my first AG which was a lager, I used a Refractometer for the first time make beer, the Lager Brix % was 9.0 (1.037) I have waited a 2 weeks and the Brix % was only down to 4.0 % (1.017) after checking for some days.

Are you using a refrac calc tool?

Fermenting wort uses a different calc when using a refrac - beersmith calcs for you

 

[Adamt]

The reason behind the difference is that alcohol also refracts light, you need to take that into account as well. Beersmith or promash or other software can work it all out for you.

 

[jeddog]

Nice work......Tar

 

[Cortez The Killer]

Or here

http://brew.stderr.net/refractometer.html

Cheers