All Tools
Fermentation pH Reference
Use these reference ranges to understand how acidity changes during vegetable fermentation.
Start (0-24 hours)
Vegetables are still close to fresh pH. Not yet acidified.
pH 6.5-5.5
Early ferment (Day 2-3)
Acidification begins; keep everything submerged and active.
pH 5.5-4.6
Active ferment (Day 4-7)
Approaching safe zone for most vegetable ferments.
pH 4.6-4.0
Finished (1-3 weeks)
Stable, tangy flavor. Refrigerate to slow activity.
pH 4.0-3.5
Long storage
Very acidic; texture may soften over time.
pH 3.8-3.3
Safety notes
- •For most vegetable ferments, aim for pH 4.6 or lowerto reduce risk of harmful bacteria.
- •Always use a calibrated pH meter or fresh test strips for accurate readings.
- •pH alone does not guarantee safety. Keep vegetables submerged, use clean tools, and refrigerate after fermentation.
Low-acid foods are not shelf-stable. When in doubt, refrigerate and discard anything with mold, off smells, or unusual colors.
Important: This calculator provides estimates for educational purposes only. Always verify measurements independently and follow established food safety guidelines. Results may vary based on ingredient quality, environmental conditions, and equipment accuracy.