The 10 problems at a glance
- White film on brine (kahm yeast — usually safe)
- Fuzzy mold on top (discard the whole batch)
- Pink, orange, or black slime (discard immediately)
- No bubbles by day 3 (check salt %, temperature, pack density)
- Brine evaporated, vegetables exposed (top up with same-strength brine)
- Soft or mushy texture (over-fermented or wrong vegetable)
- Hollow taste, no tang (under-salted or under-fermented)
- Rotten, ammonia or sewage smell (spoiled — discard)
- Brine cloudy, pearl-like (normal lactic activity)
- Won't reach pH 4.6 (insufficient acid — extend ferment, check temp)
Quick answers
White fuzzy growth on my sauerkraut: fine or bad?
It depends on the texture. A thin, flat film with no color is kahm yeast: skim it off, it's fine. Fuzzy, raised growth, especially with any color, is mold: discard the whole batch.
My pickles went soft. What happened?
Usually a ferment that ran too warm (above 75°F), or cucumbers with the blossom end left on, which holds enzymes that soften them. Trim 1/16 inch off the blossom end and keep the ferment cooler.
It smells bad: rotten eggs, ammonia or sewage.
That's spoilage, not fermentation. Discard it, and check the salt % and temperature for the next batch.
Bubbles stopped after day 5 but it's only half-sour. Is that normal?
Usually, yes. Bubbling slows as the sugar runs out, and flavor keeps developing for another week or more. Taste it to check.
It's too sour for my taste.
Move it to the fridge earlier next time. You can stop the main ferment at any point by refrigerating it.
My ferment never started bubbling at all.
Re-check the salt % (weigh it) and the temperature (put a thermometer next to the jar). Most ferments that fail to start have a salt or temperature problem.