Understanding pH

• Understanding pH may help you preserve foods safely at home. The pH of your foodstuff determines whether you should use a water-bath canner or a pressurized canner. When canning foods with a pH above 3, you may be able to lower the overall pH by adding lime juice to the mixture and then use the water bath method.
  
  

Certified Chemistry

• The U.S. Food and Drug Administration (FDA) has done extensive research on the pH of foods to ensure a safe food supply through commercial and home preparation. In the FDA's Bacteriological Analytical Manual published January 2001, the researchers established the pH of lime juice in the range 2.2 to 2.4 in their examination of canned foods.
  
  

Lime Juice is Acidic

• Testing for pH actually examines the activity of the hydrogen ions in the chemical reaction. Lime juice has been determined by many scientific tests to be acidic, regardless of changes in chemical content due to a particular variety of lime, or where and how the lime was grown.
  
  

Chemical Makeup

• pH affects chemistry. For example, when canning, be certain to follow the specific proportions needed. If your canning recipe calls for 2 tbsp. of lime juice for each quart of tomatoes, use exactly 2 tbsp.
  
  

Other Uses

• Besides use in food preparation, lime juice is used as a water supplement for livestock to encourage drinking and as a cleaning agent ingredient in detergents and surface cleaners. The pH is not often identified in these applications, but the acidic nature of lime juice makes these uses effective.