How often should I take gravity readings?

During active fermentation, daily readings are ideal but not essential. At minimum, take a reading on day 1 (OG), then every 2-3 days. Near the end of fermentation, take daily readings to confirm stability. Each sample taken is beer lost, so consider a sampling port or thief.

What does a stable gravity reading mean?

If your gravity reading does not change (within 0.001 SG) over 2-3 consecutive days, fermentation is complete. The yeast has consumed all the fermentable sugar it can. This is the only reliable way to confirm fermentation is done.

What if my gravity is stuck?

A stuck fermentation means gravity has stopped dropping but has not reached expected FG. Common causes: temperature too low (warm it up), poor yeast health (pitch more yeast), or the beer has reached its actual attenuation limit. Try raising temperature by 2-3°C and gently swirling the fermenter.

Should I worry about oxygen exposure when sampling?

During active fermentation, the CO2 blanket protects your beer. Taking quick samples with a sanitised wine thief or turkey baster is fine. After fermentation finishes, minimise sampling as oxygen exposure becomes more of a concern.

Do I need to temperature-correct my hydrometer readings?

Yes, hydrometers are calibrated to a specific temperature (usually 20°C). If your sample is warmer or cooler, the reading will be off. Use a hydrometer temperature correction calculator or let the sample cool to calibration temperature before reading.

BrewCalcs

Fermentation Log Calculator

Track and analyse gravity readings over your fermentation period.

Original Gravity (OG)

Day 1 Gravity

Day 2 Gravity

Day 3 Gravity

Day 4 Gravity

Day 5 Gravity

Day 6 Gravity

Day 7 Gravity

Enter 0 for days not yet measured

How We Calculate This

Tracking Fermentation

By logging gravity readings over time, you can calculate the daily gravity drop rate and identify when fermentation is slowing or complete. ABV = (OG - Current Gravity) x 131.25. Apparent Attenuation = (OG - CG) / (OG - 1.000) x 100.

Stability Check

Fermentation is considered complete when two consecutive readings are within 0.001 SG of each other. The calculator flags this automatically and estimates remaining fermentation based on the rate of gravity change.

Frequently Asked Questions

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Last updated: 2025-02-20

All calculations are estimates. Always verify values and adjust based on your equipment and ingredients.