How Can I Test the pH of Foods and Drinks?

[jim1174]

i want to be able to test the ph of foods and drinks so I purchesed a digital ph tester for water. Is there a better ph tester option ? If I wanted to test the ph of something like mayonnaise would I just stick the tester into the mayo or would I need to mix the mayo with water first?

 

[Borek]

Sticking the electrode into mayo won't work - that is, you will get some reading, but whether it is a pH of mayo is rather dubious.

First of all - pH is a property of water solutions, mayo is not a water solution.

Typical procedures in food industry call for a sample preparation that guarantee reproducibility and make the measurements comparable. Not that I am aware of any gold standard where such procedures are collected, that would be something like pharmacopoeia, just for the food industry. Trick is, food industry is not heavily regulated.

To some extent you can design your own procedures - say, every time mix 1 mL of mayo with 9 mL of DI and measure pH of the mixture, that will probably make your measurements reproducible and comparable between samples. Note: chances are oil from mayo will kill the electrode, so you try at your own risk.

 

[Tom.G]

You could try Litmus Paper (sometimes called Litmus Test Strips), or phenolphthalein solution. Chemical supply houses would have a good selection. Also, swimming pool supply stores sell test kits to test pH of pools.