Onions have a mildly acidic pH, generally ranging from 5.3 to 5.9. However, the exact pH can vary depending on the onion variety (red, white, yellow), its maturity, and whether it's cooked or raw.
pH Levels of Different Onion Types:
- Red onions: 5.30 - 5.88
- White onions: 5.37 - 5.85
- Yellow onions: 5.4 - 5.6
Several studies and resources corroborate this pH range. Note that pickled onions have a significantly lower pH (3.70-4.60) due to the pickling process. Furthermore, the pH of cooked onions can differ from raw onions; one study noted a decrease in pH after cooking.
Ideal Soil pH for Growing Onions:
While the pH of the onion itself is acidic, onions thrive in slightly alkaline soil with a pH between 6.0 and 7.0. This highlights the difference between the plant's internal pH and the optimal external environment for its growth.
Understanding pH in Food:
The pH scale measures acidity and alkalinity. A pH of 7 is neutral, while values below 7 are acidic and values above 7 are alkaline. Onions' slightly acidic nature contributes to their flavor profile and interacts with other ingredients in cooking.
