Just a bit of a follow up from the start of this thread....still looking for solution(s).
Summary:
1. 1 gal batch size
2. BIAB - 3 gal cooler to mash in and hold temps, Grain crush is fair, but not perfect
3. Built purified water to Pale profile ranges (see image)
4. 1.5 QT/Lb Grain minimum
5. Mashed for 1 hour 40 minutes
6. Mash temp held at 154
7. Soaked/Dipped grains in 1.25 gal water at 168
8. OG 1.038 (post boil), 1.25 gal, 51.5% Measured efficiency with refractometer....

(see images)
Yes, I am using the gravity scale on the ATC refractometer, but when I plug the Brix % into a calculator I'm getting a result not too far off from the scale. I've calibrated the refractometer with distilled water...I know they're not "made" for Wort, but adjustments can be made. The batch is already fermenting so it would only add complexity to compare to a hydrometer reading at this point. On the next batch I will compare to a hydrometer, which looking back I should have been doing all along. I guess I don't understand how I can verify the calibration and the tool be off this far....IF it is.?.? The refractometer is supposed to have ATC. I'm placing 3 drops on the lens, closing the cover, and waiting at least 30 seconds for the temp to settle. Or is there something still wrong with my process?
Below are some screenshots relevant to this batch.
I'm beyond frustrated at this point.
