Food stuff's PH

[fizzypish]

Hi,
I bought a cheap digital PH meter for the sole purpose of determining when to throw out my saniclean mix. I know you can get packets of known ph for calibration online but I was wondering is there many food stuffs with a fairly level PH that I could use? Whats best? Baking soda? Vinegar?

[Will_D]

Use cream of tartar from the grocers:

Disolve and an excess of the CoT in warm water, allow to cool and clear, make sure there is still an excess of the CoT on the bottom else its not a saturated solution . 

Then the solution created has a pH of 3.557 at 25 °C (77 °F).

CoT or Potassium Bi-Tartrate in water is a simple, single chemical "buffer solution". Despite small additions of alkalis or acids the pH remains constant.

[fizzypish]

Brilliant.
Thanks!