Having trouble with your wash? Don’t panic, fermentation can look different depending on temperature, yeast type, sugar levels and timing. Here are some common questions and what they usually mean.

My airlock has stopped bubbling, is fermentation finished?

Not always.

Airlock bubbles are only one sign of fermentation. Bubbling can slow or stop if:

• The wash has finished fermenting
• The fermenter lid is not sealed properly
• The temperature has dropped
• Fermentation has slowed down
• CO₂ is escaping somewhere other than the airlock

What to do: Use a hydrometer. If the gravity reading stays the same for 2 days in a row, fermentation is likely finished. If the gravity is still high, the wash may be stalled.

Has my yeast died?

Yeast may be stressed, stalled, or inactive if the wash is too hot, too cold, too sugary, or lacking nutrients.

Common causes include:

• Temperature too high or too low
• Too much sugar at the start
• Not enough yeast nutrient
• Old or poorly stored yeast
• Yeast pitched into liquid that was too hot
• Poor oxygen at the start of fermentation

What to do: Check the temperature first. Most distilling yeasts have a recommended temperature range on the packet. Bring the wash back into the correct range and give it time. If there is still no activity and the gravity remains high, you may need to repitch yeast.

Why does my wash smell bad?

Some smell is normal during fermentation. A wash can smell yeasty, sour, fruity, eggy, or strong depending on the yeast and ingredients used.

Common smells and possible causes:

Eggy / sulphur smell: Usually stressed yeast, lack of nutrients, or temperature issues.

Sour smell: Can be normal depending on the wash, but a sharp vinegar smell may suggest contamination or too much oxygen exposure.

Rotten / putrid smell: This may indicate infection or a badly stressed fermentation.

Strong alcohol smell: Can happen in high-alcohol washes, especially if fermented warm.

What to do: Check temperature, hygiene, ingredients, and fermentation time. If it smells strongly rotten, mouldy, or unsafe, do not use it.

Why is my wash not starting?

If there are no bubbles, no foam, and no gravity change after 24–48 hours, check:

• Was the yeast added at the correct temperature?
• Is the wash too hot or too cold?
• Was the yeast expired or stored badly?
• Was there too much sugar?
• Was the fermenter sanitised properly?
• Did the wash contain preservatives or chemicals that could stop yeast?

What to do: Bring the wash into the correct temperature range, stir gently to mix, and check gravity. If nothing changes, repitch with fresh yeast.

Why is fermentation taking so long?

Fermentation can slow down in cooler weather or if the yeast is under stress.

Possible causes:

• Low temperature
• Not enough nutrients
• High starting gravity
• Weak yeast
• Fermenter sitting on cold flooring
• Seasonal temperature changes

What to do: Use a heat belt or heat mat if needed, ideally paired with a temperature controller for better control. Stable temperature helps yeast work more consistently.

Why is my wash foaming too much?

Foaming can happen with active yeast, warm fermentation, high protein ingredients, or overfilled fermenters.

What to do: Make sure there is enough headspace in the fermenter. Avoid sealing an overfilled fermenter too tightly. Use the correct fermenter size for the recipe.

How do I know fermentation is finished?

The best way is with a hydrometer.

Fermentation is usually finished when:

• Airlock activity has slowed or stopped
• The wash has cleared or settled
• The gravity reading is stable for 2 days
• The final gravity is within the expected range for the recipe

Don’t rely on bubbles alone. Always check with a hydrometer.

Quick checklist before starting a wash

✅ Clean and sanitise all equipment ✅ Use fresh yeast ✅ Follow the recipe measurements ✅ Keep the wash within the yeast’s temperature range ✅ Use yeast nutrient if required ✅ Leave enough headspace ✅ Use a hydrometer to track progress ✅ Be patient — colder weather can slow fermentation

Need help troubleshooting your wash?

Bring your questions into Valley Hydroponics & Home Brew. We can help with yeast choice, temperature control, hydrometers, cleaners, sanitisers, nutrients, fermenters, heat belts and heat mats.