Originally Posted by NCangler17
Yooper, my lhbs said the refractometer could be used for FG. Was I lied to?
"Lied to" is strong. I'd say, no, not "lied to" but the information is incorrect.
There ARE online calculators that can be used to help convert a refractometer reading to a corresponding SG, but it's not all that accurate. It's not too bad in a beer, where the Fg is in the 1.010-1.016 range but in a wine or cider, when the reading usually goes to .990 I don't think it's even convertible. I mean .990 is below 0 brix- so how could you possibly read/convert that?
What you CAN use a refractometer for is to know if fermentation is done, although the reading isn't accurate. What I mean is this- if the reading is 5 brix today, and 5 brix in 3 days, it's done. Then you can use a hydrometer to see what the actual FG reading is.