A flat SG reading doesn't always mean a stuck wash — it can also mean the wash is finished. The trick is reading the difference. Here's the framework Broover uses internally to call it, plus the recovery playbook for genuine stuck washes in order from easy to drastic.
A wash is done when three things line up: SG at or below the target final gravity for the yeast (sugar washes typically hit 0.990–0.995, sometimes lower with turbo yeasts on dextrose); velocity flat (less than 1 SG point per day, which is essentially noise); and the wash has been at that flat plateau for at least 24 hours so it's not just a slow patch.
A wash is stuck when velocity is flat but SG is still meaningfully above target — typically 0.020 or more above FG. The yeast has stopped working before the sugar ran out. The wash will sit there forever if you don't intervene; it doesn't magically finish on day 14.
A wash is still going when velocity is above ~1 SG point per day, regardless of where SG sits. Even a slow wash dropping 2–5 points per day on day 6 is fine; don't reach for the rouse button.
1. Bump the temperature. A wash that's drifted below the yeast's preferred range stalls. Push it up 2°C (within the yeast's tolerance band — turbo yeasts like 24–32°C, ale yeasts 18–22°C). Cheap, easy, often enough.
2. Rouse the yeast. Stir the fermenter gently to re-suspend yeast that's settled to the bottom. A drill paddle on slow, or a paint stirrer for a couple of minutes. Don't aerate hard — you'll oxidise the wash. Wait 24–48 hours.
3. Top up nutrients. If you skimped on DAP / Fermaid-O / yeast hulls at pitch, this is where it bites. 5–10 g/L of a complete yeast nutrient (sources both nitrogen and minerals) often restarts a wash that's nutrient-starved.
4. Check + correct pH. A wash that's drifted below pH 3.0 stalls. Test with a strip; if low, add a pinch of calcium carbonate to nudge toward 4.0–4.5. Don't overshoot.
5. Re-pitch fresh yeast. Rehydrate a fresh dose (full pitch rate, don't skimp the second time), pitch into the wash. Last resort but reliable — a fresh active culture will finish what a tired one couldn't.
When you log a wash in Broover with a RAPT Pill, Tilt, iSpindel, or Brewfather-connected hydrometer (or even just manual SG entries), Broover analyses the trajectory and flags the wash's state on every screen it appears on — dashboard, wash list, wash detail. "Done" gets an emerald tick + "ready to strip" prompt with the settling and decant steps. "Stuck" gets an amber arrow + the recovery playbook above, ordered easy-to-drastic, so you know exactly what to try first.
You can also see this without signing up — the wash logic is the same one we describe here. The difference is Broover does the analysis on every reading automatically, so you don't have to eyeball the SG chart and guess.
Free to use right now — every feature, no payment details required. broover.app for the full workflow app, or free distilling calculators for the math without signup.