I bottled my first batch of a small batch (1gal) of a Pliney kit. Measured my OG two weeks ago using a digital refractometer (from the lab I work in) and read 21.5 brix. FG measured today, 10.7 brix. That's 10.1% ABV. I find when I convert to specific gravity from Brix the alcohol content is lower, about 7ish. Wort temp was within the kit parameters, as well as fermentation temps and duration. Which one do I use? I didn't have a hydrometer to use. The higher alcohol content concerns me. It smells great. I have to keep it in the bottles for 2weeks. Thanks!
Your first measurement seems feasible, 21.5 brix is about a gravity of 1.088 . Your second concerns me, because that suggests very low attenuation. 10.7 brix is equivalent to a finishing gravity of 1.042. This would actually calculate to something like 6% alcohol with a ton of residual sugar. I never had a Pliny, but I have to believe it finishes lower. I'm not sure how you calculated 10.1%, but that is actually probably close to what Pliny should be.
Using a tool from http://seanterrill.com/ 21.5° Brix = 1.086 10.7° Brix = 1.016 = 80% (apparent) attenuation and 9% ABV 10.7° Brix unadjusted for alcohol = 1.042 --- OP may want to let the beer condition for more than two weeks.
