Stuck Fermentation

No Bubbles in the Airlock?

A practical fermentation troubleshooting checklist for beer and wine makers.

If you don’t see bubbles in the airlock, it’s easy to assume “nothing is fermenting.” But an airlock is only a pressure indicator—it’s common for active fermentation to occur with little or no bubbling, especially when there’s a small leak, temperature changes, or a tight lid that vents elsewhere.

Use this checklist to help diagnose your Beer or Wine fermentation issues.
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Quick reality check (applies to beer & wine)

Key idea: The most reliable way to confirm fermentation is a gravity reading (hydrometer or refractometer), not airlock bubbles.

  • Take a gravity reading now

    Compare it to your starting gravity (beer OG / wine must SG or Brix). If gravity dropped, fermentation is happening—even with no airlock action.

  • Look for signs in the vessel (not the airlock)

    Beer: krausen/foam ring, haze, yeast settling. Wine: fine bubbling in the must, “cap” activity (reds), CO₂ prickle, sediment forming.

  • Check for leaks around the lid, bung, or grommet

    CO₂ may be escaping without passing through the airlock. Gently press on the lid/walls: if the airlock blips, your seal may be the issue.

  • Confirm the airlock is assembled correctly and filled properly

    Too little liquid can hide bubbling; too much can create extra backpressure. Use sanitizer solution or clean water to the fill line.

Beer: troubleshooting checklist

1) Temperature & timing

  • Has it been less than 24–72 hours?

    Many fermentations start slow, especially at the low end of the yeast’s temperature range or with higher-gravity wort.

  • Measure actual beer temperature (not room temperature)

    Most ale yeasts perform best around 64–72°F (18–22°C). If too cold, warm gradually a few degrees.

  • If too cold: warm and gently swirl

    Move the fermenter to a warmer area and swirl to resuspend yeast. Avoid shaking (oxygen pickup + mess).

2) Yeast health & pitching

  • Verify yeast age and storage

    Old/poorly stored yeast can lag or fail. Liquid yeast is especially sensitive to time and temperature.

  • Confirm you pitched enough yeast for the gravity

    High-OG beers (e.g., above 1.070–1.080) often need more yeast (or a starter) to avoid stalls.

  • If dry yeast: was it handled properly?

    Dry yeast usually works well sprinkled, but rehydration (per manufacturer) can improve performance—especially for bigger beers.

3) Wort conditions

  • Was the wort oxygenated before pitching?

    Yeast needs oxygen early for healthy growth. Lack of oxygen is a common cause of slow starts in higher gravity wort.

  • Check for sanitizer/cleaner residue

    Excess residue can inhibit yeast. Use no-rinse sanitizer correctly (proper dilution, drain thoroughly).

4) Corrective actions

  • Warm slightly, then swirl

    Raise temp gradually (a few degrees) and swirl to lift yeast back into suspension.

  • If gravity is unchanged after 48–72 hours, consider repitching

    Pitch a fresh, healthy yeast culture appropriate for the beer style and gravity.

  • Avoid adding oxygen once fermentation is underway

    If fermentation already started (gravity dropping), oxygen can cause staling/oxidation. Focus on warmth and yeast health instead.

Safety note: If you see a stalled fermentation with a very high gravity, don’t “panic shake” the fermenter—this can oxidize the beer. Use measured steps: temperature, gentle rousing, then repitch if needed.

Wine: troubleshooting checklist

1) Rule out airlock & seal issues

  • Check bung fit and carboy neck seal

    A slightly loose bung can vent CO₂ silently. Re-seat the bung and ensure the airlock is snug and upright.

  • Look for fermentation signs in the must/wine

    Fine bubbles, a light fizz, rising pulp cap (reds), sediment beginning, and gravity moving down are stronger signals than airlock bubbles.

2) Temperature & must conditions

  • Confirm must/wine temperature

    Many wine yeasts do well around 60–75°F (16–24°C) (strain dependent). Cold must can delay or halt starts.

  • Check sugar level (SG/Brix) for yeast stress

    Very high sugar musts can stress yeast. If you started extremely high, a robust wine yeast + nutrients are often needed.

3) Yeast viability & nutrients

  • Confirm yeast was rehydrated properly (if using dry wine yeast)

    Many wine yeasts benefit from correct rehydration temperature and timing (per manufacturer).

  • Add yeast nutrients if fermentation is sluggish

    Grape must (and especially fruit, honey, or juice blends) can be nutrient-poor. Nutrients often prevent stalls and off-aromas.

  • Gently stir or degas early (when appropriate)

    Early-stage stirring can help yeast, release CO₂, and improve yeast contact—use care to avoid oxygen exposure later in the process.

4) Sulfites and inhibitors

  • If you added sulfite (Campden/K-meta), did you wait long enough?

    Pitching too soon after sulfiting can suppress yeast. Many winemakers wait before pitching—verify your process and dosage.

  • Check for leftover sanitizer/cleaner in equipment

    Residue can inhibit yeast. Rinse appropriately if using cleaners that require rinsing; use proper dilution for sanitizers.

Best diagnostic for wine: Track gravity daily for a few days. If it’s dropping steadily, you’re fermenting—even if the airlock is quiet.

When to repitch yeast

Repitching is usually the right move when fermentation truly hasn’t started and your gravity isn’t moving. Use these guidelines:

  • Beer: gravity unchanged after ~48–72 hours

    Especially if temperature is in-range and you’ve ruled out leaks. Pitch fresh yeast suited to the style and gravity.

  • Wine: gravity unchanged and no must activity after ~24–48 hours (in-range temp)

    Consider a fresh pitch of a robust wine yeast and add nutrients (per product guidance), after addressing sulfite timing if used.

Tip: If you suspect yeast stress (high sugar, low nutrients, cold temp), fix those conditions before or alongside repitching.

What to collect (great for customer support calls)

If you want fast, accurate troubleshooting, gather these before calling or emailing:

  • Recipe / must details

    Beer: style, OG, batch size. Wine: must type (grape/fruit/juice), starting SG/Brix, volume.

  • Yeast info

    Strain, age/expiration, storage, whether a starter was used, and pitch method (rehydrated / sprinkled / etc.).

  • Fermentation environment

    Actual liquid temperature, vessel type (bucket/carboy/conical), and whether you see signs beyond the airlock.

  • Process notes

    Oxygenation (beer), nutrients (wine), sulfite use (wine), and any recent changes (moved locations, temp swings).

Disclaimer: This article is educational and not a substitute for product-specific instructions. Always follow yeast and nutrient manufacturer guidance and your sanitation product’s dilution and contact-time directions.