Learn to distinguish mold from normal fermentation signs

Normal: cloudy brine, bubbles, white sediment on the bottom, a thin white film on the surface (kahm yeast), sour smell, tangy taste. Bad: fuzzy spots in blue, green, black, or pink on the surface (mold), foul or rotten smell, slimy texture that was not there before. If you see actual mold, discard the batch.

Why It Works

Most "scary" things in fermentation are completely harmless. Kahm yeast (a white, flat film) is unattractive but not dangerous — skim it off and continue. True mold is fuzzy, raised, and colored. Knowing the difference prevents unnecessary waste.

Tips

• Bubbles and fizzing are signs of active, healthy fermentation
• Cloudy brine is normal and expected — it means bacteria are thriving
• The smell should be sour/vinegary, never rotten or putrid
• When in doubt, trust your nose — truly spoiled ferments smell unmistakably bad