Fermentation has slowed or stopped
Check gravity and temperature before doing anything else. The wine may be nearly finished, too cold, or genuinely stuck.
Detailed stuck-fermentation guide →
Troubleshooting
When a wine doesn't behave as expected.
Most winemaking problems can be approached calmly. Measure first, identify the likely cause, then make the smallest sensible change.
First principle
Don't guess when you can measure.
A quiet airlock, cloudy wine or an unfamiliar smell does not automatically mean something has gone wrong. Hydrometer readings, temperature checks and good notes give you evidence to work with.
Before changing the wine, ask what the measurement actually says.
Quick checks
- Take a hydrometer reading.
- Check the fermentation temperature.
- Inspect the vessel, bung and airlock.
- Review the recipe and additions.
- Give the wine time when time is the appropriate answer.
Common problems
Start with the symptom
Use the simplest explanation first, and avoid making several changes at the same time.
The airlock is quiet
An airlock is not a fermentation meter. Gas may be escaping elsewhere, or there may simply be little fermentation left.
Check fermentation →The wine is cloudy
Young wine is often cloudy. Time, settling and appropriate racking can be enough. Avoid rushing to treatment before the wine has had a chance to clear naturally.
Alcohol strength is uncertain
Use original and final gravity to estimate ABV. If you did not record an original gravity, avoid presenting an exact strength as though it were measured.
Alcohol & Strength →Yeast seems unhappy
Temperature, yeast choice, nutrient availability, sugar concentration and acidity can all affect fermentation. Review the conditions before adding more yeast.
Yeasts & Fermentation →Something tastes or smells unusual
Record what you notice and when it appeared. Avoid covering up a problem with additions until you have considered sanitation, fermentation progress and the recipe.
A calm four-step method
What to do next
1
Observe.
Look at the wine and review your notes.
2
Measure.
Check gravity and temperature where relevant.
3
Identify.
Match the evidence to the most likely cause.
4
Act carefully.
Make one sensible change, then monitor the result.
Don't panic — and don't over-correct.
Adding several ingredients or making repeated changes can make a problem harder to diagnose. Country wines often benefit from patience.
Related guidance
Go back to the basics.
The Beginner's Guide covers the complete process, while the recipe library gives you the established method for each individual wine.
Keep your notes
Dates, gravity readings, temperatures, yeast and additions turn troubleshooting into useful knowledge for your next batch.