Common Problems & Solutions

Troubleshooting guide for sauerkraut fermentation issues

Troubleshooting guide for sauerkraut fermentation issues.

No Bubbles / No Visible Activity

Problem

After several days, you see no bubbles, no activity, and it looks unchanged.

Possible Causes

  1. Too cold (below 15°C)
  2. Too much salt
  3. Wrong type of salt (iodized)
  4. Not enough time (only 2-3 days)
  5. Bubbles trapped (thick cabbage)

Solutions

Check temperature:

Check your salt:

Be patient:

Feel for bubbles:

When to Worry

Cabbage Rising Above Brine

Problem

Cabbage pieces floating above the brine, exposed to air.

Why It's a Problem

Solutions

Immediate:

  1. Push cabbage back down
  2. Check your weight is working
  3. Add more brine if needed (20g salt per litre water (about 1.5 tbsp))

Prevention:

Make Emergency Brine

20g salt (about 1.5 tablespoons)
1 litre (4 cups)
Dissolve completely
Cool to room temperature
Pour over cabbage to cover

Mold on Surface

Problem

Fuzzy spots (white, green, black, or blue) on surface or exposed cabbage.

What to Do

Small spots on surface only:

  1. Remove affected cabbage carefully
  2. Remove 1-2 inches below mold
  3. Ensure remaining kraut smells and looks good
  4. Taste a tiny bit - should be pleasantly sour
  5. If good, continue fermenting
  6. If any doubt, discard

Extensive mold:

Prevention

Mold vs. Kahm Yeast

Kahm Yeast (OK, but not ideal):

Mold (Problem):

Slimy or Soft Texture

Problem

Cabbage is slimy, soft, or mushy.

Possible Causes

  1. Too warm (above 24°C)
  2. Fermenting too long
  3. Cut too thin
  4. Variety of cabbage

Solutions

If caught early:

If very slimy:

Prevention:

Bad Smell

Problem

Smells rotten, like sulfur, or extremely unpleasant.

Normal "Funky" vs. Bad

Normal fermentation smells:

Bad smells:

What to Do

Slightly funky (days 4-7):

Truly bad smell:

Too Salty

Problem

After 2-3 weeks, still tastes predominantly salty, not sour.

Causes

  1. Not enough time (especially if cool)
  2. Too much salt (inhibits fermentation)
  3. Too cold (fermentation too slow)

Solutions

If not enough time:

If too much salt:

If too cold:

Not Sour Enough

Problem

After 3+ weeks, flavour is still bland or just salty.

Solutions

  1. Wait longer - Can take 4-6 weeks in cool temps
  2. Check temperature - Move warmer if below 18°C
  3. Taste test weekly - It will get there
  4. Be patient - Slow fermentation takes time

After 6+ Weeks Still Not Sour

Brine Overflow

Problem

Brine bubbling over the jar onto counter.

Why It Happens

Solutions

Immediate:

  1. Place jar on plate or tray
  2. Clean up overflow
  3. Wipe rim of jar
  4. Totally normal!

Prevention:

Note: Lost brine is fine - cabbage will stay submerged

Pink Colouration

Problem

Cabbage has turned pink or has pink spots.

Causes

What to Do

Light pink tinge on surface:

Deep pink/red (and you used green cabbage):

Prevention:

No Brine / Dry Cabbage

Problem

After packing, there's not enough brine to cover cabbage.

Causes

  1. Didn't massage enough
  2. Old cabbage (less moisture)
  3. Not enough salt (doesn't draw water out)
  4. Cabbage variety (some are drier)

Solutions

Immediate:

  1. Massage more thoroughly
  2. Wait 1-2 hours (brine will form)
  3. Add weight and press down
  4. If still not enough, add brine

Make brine:

20g salt (about 1.5 tablespoons) per litre water
Dissolve completely
Cool to room temperature
Pour just enough to cover

Prevention:

White Film on Surface (Kahm Yeast)

Problem

Thin white film forming on brine surface.

What It Is

What to Do

  1. Skim it off with clean spoon
  2. Wipe jar rim
  3. Ensure cabbage stays submerged
  4. Can continue fermenting
  5. Check every few days, skim if returns

Effects

Prevention

Burping Too Often or Too Little

Problem

Confused about burping frequency.

The Right Approach

If using tight lid:

How to tell if needs burping:

Signs of too much burping:

Best practice:

Alternative:

Started in Wrong Container

Problem

Used metal, reactive, or wrong type of container.

Metals to Avoid

Why: React with acid, create off flavours, can be toxic

What to Do

If caught early (within 1-2 days):

If been fermenting for week+:

Safe Containers

Questions After X Days/Weeks

After 1 Week

"Should I see bubbles?"

"Can I taste it?"

After 2 Weeks

"Is it done?"

"Still no bubbles, is it working?"

After 4 Weeks

"Still not sour enough"

"Getting too sour"

After 6+ Weeks

"Way too sour"

"Still not done"

Decision Tree: Should I Keep or Toss?

KEEP if:

✅ Smells pleasantly sour/tangy

✅ No fuzzy mold

✅ Submerged in brine (or was until now)

✅ Tastes increasingly sour

✅ Cloudy brine

✅ Normal colour (even if dull)

TOSS if:

❌ Smells rotten/putrid

❌ Fuzzy mold present

❌ Pink and slimy

❌ Extremely unpleasant smell

❌ Makes you uncomfortable

❌ When in serious doubt

Rule of thumb: If you're unsure but it passes the smell test (tangy, not rotten), it's probably fine.

Trust your instincts: Fermentation is forgiving, but if something seems really wrong, don't risk it.

Prevention Checklist

Before starting your next batch, ensure:

□ Using non-iodized salt (sea salt, kosher, pickling)

□ Proper salt ratio (~2% by weight or 20g per 900g (about 1.5 tbsp per 2 lbs))

□ Clean equipment (not sterile, just clean)

□ Massage cabbage thoroughly (10+ minutes)

□ Pack tightly to remove air pockets

□ Cabbage covered by brine (1-2 inches)

□ Adequate weight to keep cabbage down

□ Fermenting at 18-24°C

□ Out of direct sunlight

□ Placed on tray to catch overflow

□ Plan to leave alone for first 7 days

Following this checklist prevents 90% of problems!

Still Have Questions?

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