Shelf-life programme

A real-time study stores the product under its declared conditions and tests it at intervals across the full claimed life plus a margin. It is the only study that directly evidences the date you print. It is also slow, which is why it should start before you need the answer.

An accelerated study raises the storage temperature to force change faster. It gives an indicative answer in weeks rather than months, which is useful for development and for narrowing options. It does not replace a real-time study for the final claim, and any laboratory telling you otherwise is selling you something.

Microbiological stability, because that is usually the safety-limiting factor. Chemical stability covering pH, water activity, and oxidation indicators like peroxide value for fat-containing products. Sensory assessment, because a product frequently becomes unacceptable to eat well before it becomes unsafe to eat.

The endpoint is whichever of those three fails first. Studies that only test microbiology routinely produce shelf lives that are technically safe and commercially useless.

The limiting factor is often sensory, not microbiological. A study that only counts organisms will miss it.

Where the product is ready to eat and supports growth, a challenge test deliberately inoculates it with the organism of concern and measures whether that organism grows across the claimed life. It is the strongest evidence available for a shelf-life claim on a high-risk product, and for some customer specifications it is required rather than optional.

We write a study plan before anything starts: the storage conditions, the intervals, the parameters at each interval, the acceptance criteria and the number of units required. You approve it, and the plan becomes the record. Nothing is decided retrospectively.