Fermentation Stuck at 1.020? 5 Rescue Methods That Actually Work

Your fermentation started strong, then stopped at 1.020 specific gravity. Sugar remains, activity has ceased, and your wine is stuck. Do not despair—stuck fermentations are rescuable if you act correctly.

Confirm It Is Actually Stuck

Before intervention, verify the problem:

• Check temperature: Cold wine ferments slowly. Warm it and wait 24-48 hours.
• Check SG twice: Take readings 24 hours apart. No change = truly stuck.
• Taste it: Stuck wine tastes sweet. Dry wine that finished at unusual SG is not stuck.

Why Fermentations Stick

Nutrient deficiency: Yeast starved of nitrogen give up. Most common cause.

Temperature extreme: Too cold and yeast hibernate. Too hot and they die.

High alcohol: Some yeasts surrender before reaching their stated tolerance.

Toxic environment: High SO2, excessive tannins, or competition from wild yeast can kill your cultured strain.

Underpitching: Not enough yeast to finish the job.

Method 1: Environmental Correction

Try the gentlest intervention first:

1. Warm wine to 70-75°F
2. Add yeast nutrient (1/2 tsp DAP per gallon)
3. Stir vigorously to resuspend yeast and add oxygen
4. Wait 24-48 hours

If fermentation restarts, monitor closely and maintain temperature.

Method 2: Restart Yeast Starter

If Method 1 fails, introduce fresh yeast with momentum:

1. Make a starter: 1 cup warm water + 2 tbsp sugar + rehydrated yeast (use a high-alcohol-tolerant strain like EC1118)
2. Let starter ferment actively (4-8 hours until foaming)
3. Add 1 cup of stuck wine to starter
4. Wait for fermentation to continue (2-4 hours)
5. Double the volume with more stuck wine
6. Continue doubling until starter approaches stuck wine temperature and gravity
7. Add the whole starter to stuck wine

This “step-feeding” acclimates new yeast gradually to the hostile environment.

Method 3: Go Nuclear (EC1118 Direct Pitch)

For stubborn cases:

1. Rehydrate 2 packets of EC1118 (known for restarting stuck fermentations)
2. Add Go-Ferm or similar rehydration nutrient
3. Pitch directly into warmed wine
4. Add DAP
5. Stir twice daily

EC1118 is aggressive enough to finish in conditions that killed other yeasts.

Method 4: Accept Reality

If all methods fail, you have options:

• Stabilize and sweeten: Add potassium sorbate and sulfite to prevent refermentation. Embrace the residual sugar as a feature.
• Fortify: Add brandy or neutral spirits to raise alcohol, killing yeast and preserving sweetness. You have made a dessert wine.
• Blend: Mix with dry wine to reduce overall sweetness.

Prevention

Stuck fermentations are easier to prevent than fix:

• Use adequate yeast nutrient from the start
• Pitch sufficient yeast for must gravity
• Maintain appropriate temperature throughout
• Aerate must during the first third of fermentation