The pH check, step by step

Calibrate first, every session

Not at the start of the season. A meter drifts and buffers age, and the one measurement your whole regulatory position rests on is not the place to assume an instrument is still right because it was in July. Calibrate against fresh buffers, on a bench, before the readings that matter.

Measure the right thing

The number that counts is the equilibrium pH of the finished product, not the pH of the brine you mixed. Those differ, sometimes considerably, because the vegetable and the liquid exchange acid until they settle. Measuring the brine and recording it as the product is the most common way a maker ends up with a number that was never true of anything.

At room temperature, on a settled jar

Temperature affects the reading, and a jar still equalizing is not the product yet. Let it come to room temperature and let the contents settle, then measure. A reading taken warm, in a hurry, on the day of packing is a number about that moment rather than about the product.

Record it against the batch

The reading, the date, the meter, the buffers and which batch it was. That record is the evidence the process was followed, and it is the thing that is asked for rather than the thing you remember. A number in a notebook with a batch code beside it is worth more than a confident recollection.

If it is out

The batch is not shelf stable, and that status does not change because the next batch was fine. Refrigerate it, sell it as a short-life product, or discard it, but do not reclassify it by taking a second reading until one comes out right.

References