Gravity
Gravity · fermentability and performance tracking
Gravity is the most useful daily metric in the brewhouse. It tells you where sugar started, how much yeast consumed, and whether fermentation finished as intended.
| Metric | Meaning | Typical Use |
|---|---|---|
| OG (Original Gravity) | Sugar concentration before fermentation | Predict ABV potential |
| FG (Final Gravity) | Residual density after fermentation | Assess dryness/body and completion |
| Apparent Attenuation | Percent gravity drop during fermentation | Compare yeast performance batch to batch |
Practical Measurement Workflow
Take OG on chilled wort before pitch. Track gravity during fermentation using the same instrument and temperature correction approach each time. Confirm FG with two stable readings 24 hours apart.
GF-Specific Notes
GF worts can vary in fermentable sugar profile even at similar OG values. That means two batches with matching OG may finish at different FG. This is why gravity trend data is more useful than single-point readings.
Common gravity mistakes:
- Comparing readings without temperature correction
- Changing instruments mid-batch
- Declaring fermentation complete from one FG reading
What good gravity tracking delivers:
- Faster detection of stalled fermentation
- Better ABV and body predictability
- Clearer root-cause analysis across batches
Source Notes
Gravity management based on standard brewing lab practice and production logging workflows.