Guide

Troubleshooting lacto-fermentation: 10 problems and authoritative fixes

Fermentation is forgiving, but not infinitely. This guide covers the 10 problems home fermenters actually encounter — from the scary-looking-but-harmless to the toss-it-immediately — with clear action items for each.

What this guide covers

  1. 1. White film on brine (kahm yeast — usually safe)
  2. 2. Fuzzy mould on top (skim ¼ inch + brine, then re-evaluate)
  3. 3. Pink, orange, or black slime (discard immediately)
  4. 4. No bubbles by day 3 (check salt %, temperature, pack density)
  5. 5. Brine evaporated, vegetables exposed (top up with same-strength brine)
  6. 6. Soft or mushy texture (over-fermented or wrong vegetable)
  7. 7. Hollow taste, no tang (under-salted or under-fermented)
  8. 8. Strong off odours (acetone = wrong yeast; sulphur = brassicas, normal)
  9. 9. Brine cloudy, pearl-like (normal lactic activity)
  10. 10. Won't reach pH 4.6 (insufficient acid — extend ferment, check temp)

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