A practical guide to identifying and fixing common faults in home distilling
Distilling your own spirits is a rewarding process, but even experienced distillers occasionally encounter off-flavours. Whether your neutral spirit smells like rotten eggs, nail polish remover, or syrupy sweetness, the good news is: most faults are fixable, and every batch is a learning opportunity.
Here’s how to identify the three most common off-flavours in home distilling and what to do about them.
1. Sulfur: Rotten Eggs, Burnt Matches, or Cabbage
What it smells like: Sharp, unpleasant, and unmistakably foul. Often described as rotten eggs, burnt rubber or, if you’re from New Zealand, Rotorua!.
Likely causes:
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Stressed yeast: High fermentation temperatures or nutrient deficiencies.
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Poor clearing: Yeast cells breaking down during distillation.
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Low-quality wash: Incomplete fermentation or contamination.
Fixes:
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Use Turbo Clear to remove yeast before distilling.
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Ensure proper fermentation temperature (18–24°C for most turbo yeasts).
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Aerate the spirit post-distillation or use copper in the column or collection path. Copper reacts with sulfur compounds and neutralises them.
Pro tip: If using a T500, make sure your column has copper mesh or saddles installed.
2. Solvent: Nail Polish Remover or Paint Thinner
What it smells like: Harsh, chemical, and volatile. Often linked to acetone or ethyl acetate.
Likely causes:
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Overheating during fermentation or distillation
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Poor cuts: Collecting too much of the heads.
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Contaminated equipment or plastic leaching.
Fixes:
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Discard the first 50-150 mL of distillate per 25 L wash (the “heads”).
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Keep distillation temperature steady, don’t rush the boil.
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Use food-grade equipment and avoid plastic contact with high-proof alcohol.
Pro tip: If the smell is strong, redistill the spirit after diluting to 40% ABV.
3. Sweetness: Syrupy, Fruity, or Unfermented Notes
What it tastes like: Sweet, sticky, or oddly fruity, especially in neutral spirits.
Likely causes:
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Incomplete fermentation: Residual sugars left in the wash.
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Low yeast activity: Old yeast, poor nutrient balance, or incorrect pH.
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Poor clearing: Yeast and sugars carried into the boiler.
Fixes:
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Confirm final gravity with a hydrometer before distilling.
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Use fresh yeast and proper nutrients (e.g., Still Spirits Turbo Yeast + Turbo Carbon).
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Always clear your wash with Turbo Clear or allow extended settling time.
Pro tip: A sweet spirit may also indicate contamination, check for wild yeast or bacterial activity.
Final Thoughts: Taste, Test, and Tweak!
Off-flavours are frustrating, but they’re also diagnostic clues. By understanding what went wrong, you can adjust your process and improve your next batch. Keep notes, taste critically, and don’t be afraid to redistill or blend if needed. Remember, spirits can be very forgiving!