Variation in pH readings

Can someone please help.
I am having major issues with a product which is tested for pH at production and is within tolerance. This is sent to our customer same day and is being tested on receipt and is out of spec. We have tried several different pH meters and also had the customer on site. There seems to be a change from 3.9-4.0 when made to 4.6 upwards after dispatch. What could be happening. The tolerances are 3.8-4.4pH. We have sent product to our external lab who confirm the pH has risen significantly

Dear P Ashley,

product = ? Someone here may be familiar.

History? Change in production / ingredients ? Known sensitivity ?

So many possible variables unfortunately.

Rgds / Charles.C

I agree with Charles
we had similar problem with citric acid in one of our product.
one bag (25kg) of the same batch received was not accurate PH less.
we sent it back and still waiting for their reply.
check all your ingredients(conform to the specifications),conditions of storage and process, before may be ending to change formulation and getting more problems.
what about PH electrode, buffer solutions?
bibi

Dear P Ashley,

product = ? Someone here may be familiar.

History? Change in production / ingredients ? Known sensitivity ?

So many possible variables unfortunately.

Rgds / Charles.C

product is a houmous with extra virgin olive oil.
product has been on sale for over a year and only recently have we had issues.
we had the customer on site and tested the product with them and had readings of 3.9 this was sent to an external lab with results of 4.4.
Three seperate ph meters were used of 2 different sorts all read 3.9.
lemon juice is the key ph attributor which is tested on receipt and was tested in front of the customer at 2.3pH well within spec. all buffers were new as were one of the pH meters.

product is a houmous with extra virgin olive oil.
product has been on sale for over a year and only recently have we had issues.
we had the customer on site and tested the product with them and had readings of 3.9 this was sent to an external lab with results of 4.4.
Three seperate ph meters were used of 2 different sorts all read 3.9.
lemon juice is the key ph attributor which is tested on receipt and was tested in front of the customer at 2.3pH well within spec. all buffers were new as were one of the pH meters.

Sounds like the proteins in the chickpeas could be acting as a buffer and you may have to target a lower pH.

Regards,

Tony

may be Tony but
Ashley is the reading ph4.4 just the lab readings, or the customer reading in their site.
do keep sample of your batch to be tested after few hours.
few taughts
bibi

hi Ashley
interested to have your follow up
bibi