I think I'm calculating this correctly...

[Ballixxe]

OG was 1.070
FG is 1.020
With correction for ETOH for FG Brix is 5, which would put me at 10.19% ABV, correct?

 

[jschein]

No, it’s about 6.56%.
Use this calculator, no corrections if you are using hydrometer samples.

https://www.brewersfriend.com/abv-calculator/

 

[DBhomebrew]

This is a cider? I'm going to guess you're using a refractometer?

 

[Ballixxe]

correct. I work in a clinical lab and used our refractometer. my reading today (day 8 since pitch) was 1.020 uncorrected. I used an online calculator to account for ETOH and this came out to 5 BRIX, if I did it right....

 

[DBhomebrew]

What was your OG and observed FG in Brix?

Doing some backward computation, I'm seeing the following.

1.070 OG
1.020 apparent FG, equivalent to 5Brix observed & uncorrected

1.070 & 5Bx into the calculator gives an actual FG of .991, 10.19%ABV

 

[dmtaylor]

For refractometer, you'll get a reasonable estimate of ABV here:

https://www.brewersfriend.com/refractometer-calculator/
So yeah, about 10% ABV or whatever.

 

[Ballixxe]

Yes. That was my calculation as well.
However, let me be a explain a little better as I did not in my OP.
The uncorrected, plain old refrac OG was 1.070.
The uncorrected refrac @ 8 days is 1.020.

 

[Raptor99]

I find that it is more straightforward when using a refractometer to record only the Brix and ignore the SG scale in the instrument. That way you won't have an "uncorrected SG" in your records. The refractometer reads the actual Brix, but to calculate the current correct SG once fermentation has started, I use the original and current Brix in this calculator: Homebrew Refractometer Calculator