I'm trying to use the Refractometer tool in BeerSmith 2 to measure the gravity of wort while it's fermenting.
Over the past few brews, I've sampled several batches of unfermented wort, and got the results below. They seem reasonable enough.
Using the last row in that table, I calibrated BeerSmith's hydrometer tool:
That seems fine, and when I use the Unfermented Wort Gravity option in BeerSmith, it outputs a Corrected Gravity that's pretty close to my hydrometer readings. Okay, cool.
The problem is, when I use the Fermenting Wort Gravity option, the calculations are way off. I punched in a refractometer reading for a batch that's been brewing for 4 days:
BeerSmith tells me the SG is 1.015, but a hydrometer reading on the same wort gives 1.024, so BeerSmith's number is way too low.
What could I be doing wrong here? What potential sources of error should I look at?
Over the past few brews, I've sampled several batches of unfermented wort, and got the results below. They seem reasonable enough.
Sample Temp | Refractometer (Brix WRI) | Hydrometer (SG) |
20 | 8.5 | 1.034 |
36.7 | 11.5 | 1.046 |
30 | 9.5 | 1.039 |
35 | 11.4 | 1.046 |
Using the last row in that table, I calibrated BeerSmith's hydrometer tool:
- Calculation = unfermented wort gravity
- Distilled water reading: 0.2 Brix
- Refractometer reading: 11.4 Brix
- Hydrometer reading: 1.046
- => Brix correction factor: 0.983
That seems fine, and when I use the Unfermented Wort Gravity option in BeerSmith, it outputs a Corrected Gravity that's pretty close to my hydrometer readings. Okay, cool.
The problem is, when I use the Fermenting Wort Gravity option, the calculations are way off. I punched in a refractometer reading for a batch that's been brewing for 4 days:
- Calculation = fermenting wort gravity
- Refractometer reading: 7 Brix
- Original gravity: 1.046 SG
- => Corrected gravity: 1.015 SG
BeerSmith tells me the SG is 1.015, but a hydrometer reading on the same wort gives 1.024, so BeerSmith's number is way too low.
What could I be doing wrong here? What potential sources of error should I look at?