Fermentation Time Chart
Interactive chart showing fermentation timelines at different temperatures. Select your ferment and temperature to see day-by-day progression.
Sauerkraut Fermentation at 18°C (65°F)
At 18°C (65°F), sauerkraut ferments slowly, developing complex flavors over 3-4 weeks. This cooler temperature is ideal for a crisp, nuanced kraut.
Minimum
14 days
Optimal
21 days
Maximum
28 days
Day-by-Day Timeline
Days 1-3
Initial fermentation begins. Brine starts to cloud.
What to look for:
- Brine becoming cloudy
- Small bubbles appearing
- Slight sour smell beginning
Action: Ensure cabbage stays submerged. Check daily for any floating pieces.
Days 4-7
Active fermentation. Bubbling increases.
What to look for:
- Steady bubbling visible
- Sour smell more pronounced
- Brine very cloudy
- Slight tang when tasted
Action: Continue to monitor. Press down weight if cabbage rises.
Days 8-14
Fermentation slows. Sourness develops.
What to look for:
- Bubbling decreases
- Consistent sour taste
- Cabbage softening slightly
Action: Taste daily to monitor sourness level.
Days 15-21
Maturation phase. Flavors deepen.
What to look for:
- Minimal bubbling
- Complex, tangy flavor
- Pleasant sour aroma
- Crisp-tender texture
Action: Taste test. Move to cold storage when desired flavor is reached.
Days 22-28
Extended fermentation for deeper flavor.
What to look for:
- Very tangy taste
- Softer texture
- Richer color
Action: For strong sauerkraut, continue. Otherwise, refrigerate.
Taste Progression
| Day | Expected Flavor |
|---|---|
| Day 3 | Mild, slightly salty, fresh cabbage taste |
| Day 7 | Light tang beginning, still mostly fresh |
| Day 14 | Noticeable sourness, pleasant tang |
| Day 21 | Well-developed sour flavor, complex taste |
| Day 28 | Strong sour flavor, deep fermented taste |
Safety Notes
- Always keep cabbage submerged under brine
- Use a 2-3% salt ratio by weight
- Discard if you see fuzzy mold (not flat kahm yeast)
- The sour smell is normal; foul or rotten smell is not
- White film (kahm yeast) can be skimmed off
Frequently Asked Questions
Why ferment at 18°C (65°F)?
Can I ferment sauerkraut faster?
How do I know when it is done?
How Temperature Affects Fermentation
cold
15-18°C (59-65°F)
Slower, crunchier, more complex flavors
moderate
18-22°C (65-72°F)
Balanced speed and flavor development
warm
22-27°C (72-80°F)
Faster fermentation, softer texture
hot
27°C+ (80°F+)
Rapid fermentation, may need monitoring