During my last 2 brews I've had some inconsistencies in measurements i've seen between my refactometer pre-boil, post boil, and my hydrometers. So I decided to perform a 2-point calibration check on all my equipment.
I used distilled water as a base for both samples. The first sample was straight distilled water. The second sample was a 12% w/w solution - 36g sucrose in 264g distilled water (a.k.a 12 Brix/1.048 SG) of sucrose and distilled water. The 12% solution was prepared on scale that weighs to 0.01g and was calibrated immediately prior to preparing the sample. All hydrometer tests performed at 60F. Refractometer tests performed at room temp (72F).
Measurement results as follows:
Hydrometer 1 (60F/60F) - very old
Hydrometer 2 (60F/60F) - new
Refractometer w/ ATC (scale in Brix)
So the conclusion I come to is that both of my hydrometers have shifted, the newest by 2 points, and the oldest by 5-6. I am comfortable that can be explained. But I am more confused by the refractometer reading though. How can it be explained that it is spot on at 0, but off by 0.4 Brix at this low of a measurement? The only calibration option for the refractometer shifts the scale up or down.
I'm further confused by my last brew where i measured 11.2 Brix pre-boil, 12 Brix post boil, and only 1.042 in the Hydrometer. That's not even in the ball park. I can't explain that at all.
Any thoughts?
I used distilled water as a base for both samples. The first sample was straight distilled water. The second sample was a 12% w/w solution - 36g sucrose in 264g distilled water (a.k.a 12 Brix/1.048 SG) of sucrose and distilled water. The 12% solution was prepared on scale that weighs to 0.01g and was calibrated immediately prior to preparing the sample. All hydrometer tests performed at 60F. Refractometer tests performed at room temp (72F).
Measurement results as follows:
Hydrometer 1 (60F/60F) - very old
- Distilled Sample - 1.006
- 12% w/w Sample - 1.053
Hydrometer 2 (60F/60F) - new
- Distilled Sample - 1.002
- 12% w/w Sample - 1.050
Refractometer w/ ATC (scale in Brix)
- Distilled Sample - 0 Brix
- 12% w/w Sample - 11.6 Brix
So the conclusion I come to is that both of my hydrometers have shifted, the newest by 2 points, and the oldest by 5-6. I am comfortable that can be explained. But I am more confused by the refractometer reading though. How can it be explained that it is spot on at 0, but off by 0.4 Brix at this low of a measurement? The only calibration option for the refractometer shifts the scale up or down.
I'm further confused by my last brew where i measured 11.2 Brix pre-boil, 12 Brix post boil, and only 1.042 in the Hydrometer. That's not even in the ball park. I can't explain that at all.
Any thoughts?