Fermenting

The Fermenting tab is the live fermentation surface — where a finished brew day becomes a tracked ferment. You log gravity and temperature readings over the batch’s days and watch attenuation close on terminal. A full-width status strip holds the headline numbers; below it a Probe readings chart and a Readings log record every sample, while a side rail tracks attenuation, the fermentation profile, and the dry-hop schedule. Most of what you see here is derived from your readings, shown against the recipe’s targets.

ReferenceBrew log · Fermenting tab·Updated Jun 2026

Readings save the moment you log them. The status strip's attenuation and forecast numbers are computed from the readings you log — they sharpen as you add more samples — and are shown against the recipe's targets.

Fermentation status

A six-cell strip across the top of the tab. Some cells are measured, some forecast, each carrying its recipe target below it.

Current SG: your most recent logged gravity, with the time it was taken below it.
Apparent atten.: how far the wort has attenuated so far (from OG to the current gravity), against the target attenuation the recipe implies.
Last 24h: the gravity change since your previous reading — −N pts as it falls, +N if it rises.
Ferm. temp: the temperature of your latest reading, against the recipe's target ferment temperature.
Forecast FG: the projected terminal gravity, extrapolated from your readings, against the target FG.
ABV (proj.): projected ABV from the OG and the forecast gravity, against the target ABV.

How the forecast works

Fermentation slows as it approaches terminal, so gravity follows a curve that flattens out rather than a straight line. Forecast FG extrapolates your logged readings along that curve to estimate where the gravity will settle, and the days to terminal estimate is given as a range (for example “another 2–4 days”) rather than a single date, because the tail is the least predictable part. Projected ABV is then computed from your OG and that forecast gravity. Every one of these sharpens as you log more readings.

Probe readings

The wide card on the left charts your readings over the days of the ferment. A row of tabs switches which metric you’re looking at.

Metric tabs: Gravity, Temperature, and Battery. Each tab shows that metric's latest value; selecting one redraws the chart and readout for it.
Readout: the current value of the selected metric, the change since the previous reading, and which day of the ferment that is.
Chart: your logged readings plotted against the day axis, with a dashed target line — a gentle attenuation curve for gravity, a flat hold line for temperature. Battery has no target.

Probe device vs. manual. If the batch has a linked probe (such as a floating hydrometer), the card shows the device type, its last sync time, and a battery readout in the footer, and the Battery tab appears. Without a device the card reads manual readings, the Battery tab is hidden, and you enter every sample yourself in the Readings log below.

Readings log

The table beneath the chart is the full history of samples, newest first. Each row shows when the reading was taken (day number, date, and time), the gravity — with the point drop since the previous sample beside it — and the temperature. The most recent row is highlighted, and each row can be deleted (a small confirm appears first).

Log a reading. The entry row at the bottom takes a date, a time (defaulting to now), a gravity, and a temperature, then Log reading. You only need one of gravity or temperature — log a temperature-only check or a gravity-only sample freely. Pressing Enter in any field logs the row.

Attenuation

The top card of the side rail turns the gravity numbers into a single progress read.

Readout: the current apparent attenuation as a large percentage, with the target percentage beside it and how many gravity points remain to reach it.
Gauge: a bar that fills toward the target, with a tick marking the target itself.
Scale: the three gravity landmarks — OG, now, and the target FG — left to right.
Yeast hint: the yeast strain and its rated attenuation, plus a day-by-day estimate of how many more days until the ferment reaches terminal.

Fermentation profile

The middle rail card lists the planned fermentation steps (for example a primary rest, then a diacetyl rest or cold crash). The header counts progress — for example 1 of 3 done — and names the profile.

Marker: the circle at the left of each step. It shows the step number, or a check once done. Tap it to change the step's state: an upcoming step marks done, the active step advances to the next, and a done step goes back to upcoming.
Status: each step reads next, in progress, or done, with its target temperature beside it.
Name + duration: the step name and its length in days; the active step also shows day N of M of its run.

Dry hop schedule

The bottom rail card lists every dry-hop charge, grouped by the day it’s due. Each group shows the day number and its calendar date; the earliest group still pending is badged next, and a fully-dosed group is badged done. The header totals the additions and their combined weight.

Each charge is a row you tap to mark dosed — it strikes through and checks off — showing the variety, the weight, and a form chip (cryo charges are highlighted apart from pellet).

How to track fermentation

1Log a gravity and temperature reading whenever you take a sample — or let a linked probe sync them for you.
2Watch the Attenuation gauge and Forecast FG close on the recipe's targets as readings accumulate.
3Work the fermentation profile — tap a step's marker to advance through primary, any rests, and the crash.
4Tick off each dry-hop charge on the day it's due.
5When the gravity is stable at terminal and the batch is packaged, advance to 04 · Done.

See also: the Brews overview for the stage timeline, the Brewing tab for brew day, and the Completion tab for packaging and closeout.