Refractometers

[Alun]

Hey everyone,

                      Does any one have experience with using refractometers to measure the gravity of wort and fermenting beer?

example refractometer

Also are there any down sides to the digital ones?

digital example for wine

Cheers

[David Upex]

So why doesn't a refractometer work very well when measuring the SG from the fermenter? and what do the calculators do that make it more accurate? 

It seems to me that taking a few drops out of the fermenter rather than enough to float my hydrometer will be much better?

[Ralph]

Refractometers measure the angle that the sugars in the solution change the light... the alcohol in solution messes with this measurement (alcohol probably changes the angle as well, but to a different amount). The alcohol can be compensated for.

[Grant R Baker]

+1 to what Ralph said.

Links like this http://onebeer.net/refractometer.shtml or http://www.northernbrewer.com/refractometer-calculator/ help... for some reason they all use the Brix measurement and not the gravity... but that you can see that easily through your refractometer or here http://www.winning-homebrew.com/specific-gravity-to-brix.html

[Grant R Baker]

Wee update to this... I just used a refractometer to test if the beer had finished fermenting.

FG was 1.034.  We I know is not right, so I converted it to Brix using the other scale in the view finder... thus

FG 1.034 = about 9 Brix.

OG was 1.071 so about 18 Brix...

then used the Brix Calc and got 1.011 ish...

    so it looks finished. Will confirm with a Hydrometer in a few days.