pH buffer life

[Randoneur]

Do pH buffer have a short life. I opened new packes of 7.01 and 4.01 buffer in mid august from packets I had purchase a year ago. They produced and error of 0.64 when I used them to calibrate my meter.
I did not discover this for a couple of weeks, when the pH and TA numbers on my grapes did not make sense during ripeness testing.


Did one of the buffers go bad or was it just bad to begin with? Any thoughts?

 

[ibglowin]

Have you checked/replaced the batteries from the pH meter recently?

I know this from experience that weak batteries cause errors in calibration and stability.

Aside from that, as long as they are sealed tightly they should last a year or more. I have some that are probably 2.5 years old, still sealed in pouches that dial right in as long as I had fresh batteries!

 

[Randoneur]

Yes, my meter checks and displays battery status each time it is turned on. My new buffer sachets were purchase in August '10. The bad sachets were purchase 18 months ago.


I know the error was 0.64 because that is the shift back to normal when I opened a new set of buffer sachets last week because:


1) I had three wine samples from last previousvintages that I opend and checked before and after switching the buffer.
2) Each sample had a record of pH as it went into the bottle.
3)I compared readings that I took to readings that I had recorded while using the previous buffer and to the as bottled pH.


The 0.64 difference repeated on the 3 different wine samples from records to bad buffer and from bad buffer to new buffer.

 

[ibglowin]

Sounds like the buffers went out of wack for sure.

Oh and welcome to the FVW Forums!