Using a lab, and what to send
Updated
A lab answers questions your bench cannot. It is also the step producers skip and then need urgently, usually because a buyer asked.
What to test and when
Before the process authority. They will want pH and often water activity on the actual product, and sending it with the submission saves a round trip.
When a buyer requires it. Wholesale and retail accounts routinely ask for a current analysis, and some want it annually.
When something changes. A new pepper source, a different vinegar strength, a reformulation. The bench pH tells you about that batch; the lab tells you whether the product still matches its filing.
For a nutrition panel, if you need one, which is a separate analysis from safety testing.
What to send
Finished product in the container you actually sell, sealed, with the batch code on it. Not a jar of the mix, not a sample from partway through the process. The lab is measuring the thing the customer receives.
Send more than they ask for. A second sealed sample lets them repeat a result without another shipment, and a retained bottle from the same batch stays with you.
Tell them what it is and what you are asking. A lab that knows it is an acidified sauce being tested against a scheduled process reports differently from one handed an unlabeled bottle.
Reading the result
Compare it against your scheduled process limits, not against a general threshold. Your process may require 4.0 where the regulation says 4.6, and the number that matters is yours.
Keep the report with the batch records. A current analysis is what a buyer asks for and an old one raises the question it was meant to settle.
What testing does not do
It does not make a batch safe, it tells you whether it was. Testing every batch is not a substitute for a process that produces safe batches, and no realistic sampling plan finds a hazard that occurs in one bottle.
The control is the process. The lab confirms the process is doing what it was designed to do, which is a different and smaller job than it appears.