Yogurt, a popular fermented milk product, often sparks debate about its pH level and whether it’s beneficial or detrimental to health. While milk itself falls within a slightly alkaline range (pH 6.7-6.9), the fermentation process dramatically alters yogurt’s pH, making it acidic. Let’s break down what this means and why it matters.
Understanding pH
pH is a measure of how acidic or alkaline a substance is. The scale ranges from 0 to 14. A pH below 7 indicates acidity, a pH above 7 signifies alkalinity (or basicity), and a pH of 7 is neutral. Pure water generally has a pH of around 7, although sources and treatments can shift it slightly in either direction.
The Fermentation Process and Yogurt’s pH
Yogurt is produced by heating pasteurized milk and then introducing live bacteria to it. Key bacteria include Lactobacillus bulgaricus and Streptococcus thermophilus, with other beneficial probiotic bacteria also frequently added. During fermentation, these bacteria convert lactose (milk sugar) into lactic acid. This process lowers the pH of the yogurt, ultimately resulting in a pH of 4.6 or lower – making it acidic.
- Fermentation Time Matters: The longer yogurt ferments, the more lactic acid is produced, and the lower the pH becomes. Shorter fermentation periods lead to a higher pH and a sweeter taste.
- Variety of Bacteria: Different strains of bacteria influence the fermentation process, contributing to a wide range of flavors and slight variations in pH.
Why Yogurt Remains a Healthy Choice
Despite its acidic nature, yogurt is considered a valuable addition to a healthy diet for several reasons:
- Nutrient-Rich: Yogurt is a good source of essential vitamins and minerals, including vitamins A, B2, and B12, calcium, potassium, and phosphorus.
- Recommended Dairy Intake: Dietary guidelines recommend that most adults consume around 3 cups of dairy products daily, and yogurt is a convenient and nutritious option.
- Probiotic Benefits: Fermented foods like yogurt are rich in probiotics, which are beneficial for gut health and can help reduce inflammation.
Choosing the Right Yogurt
To maximize the health benefits of yogurt, consider the following:
- Live and Active Cultures: Look for yogurts that explicitly state they contain live and active cultures.
- Low-Fat or Fat-Free: Opt for low-fat or fat-free varieties to reduce saturated fat intake.
- Limit Added Sugars: Be mindful of added sugars, as some yogurts contain significant amounts.
In conclusion, while yogurt is technically an acidic food due to the lactic acid produced during fermentation, its nutritional benefits and probiotic content make it a healthy and delicious choice for most people. Choosing yogurt with live and active cultures, low in fat, and with minimal added sugars will best support overall health and well-being.
Meet Our Experts
Reyna Franco, RDN, and Siddhi Camila Lama, MS, PhD, CNC, CPT, contributed their expertise to this article. Reyna Franco is a registered dietitian nutritionist with extensive experience in medical nutrition therapy and corporate wellness consulting. Siddhi Camila Lama is an independent science and gastronomy writer with a background in bioengineering and nutrition. Their combined knowledge provides valuable insights into the science and health implications of yogurt consumption
