Ask a room of technical managers where their shelf life came from and you get two kinds of answer. Some can hand you a test plan, dated results and a revalidation date. The rest say some version of “it's always been twelve months.” Both products are on shelf. Only one of them has a shelf life anybody can defend.
Use-by or best-before is a safety decision
The two dates do different jobs, and the difference is legal rather than stylistic. A use-by date is about safety: it goes on highly perishable food that could become a risk to health, and selling past it is illegal. A best-before date is about quality: the product may not be at its best afterwards, but it is not unsafe and it can still lawfully be sold.
Which one applies should fall out of your hazard analysis, not out of a commercial preference for a longer number. If your product supports the growth of pathogens under reasonably foreseeable storage, you are in use-by territory and the evidence bar goes up accordingly.
What validation actually involves
Validation means proving the life you print, rather than asserting it. In practice a defensible programme rests on four things, tested across the intended life and specifically at the end of it.
Test against defined pass criteria at intervals through life. Where growth of a pathogen is credible, a challenge test or predictive modelling may be needed.
Organoleptic assessment for taste, texture, aroma and appearance, conducted under hygienic controls, which auditors increasingly expect to see recorded.
pH and water activity are the hurdles doing the preserving. Record the ranges, because a formulation change that moves them changes your shelf life.
Test in the actual pack, at the actual storage temperature, through the actual distribution route. A life proven in ideal conditions is not the life the product gets.
Then it needs revisiting. Standards expect shelf life to be validated with records kept and reviewed annually, and re-examined whenever something material changes, a reformulation, a new supplier, different packaging, a new storage or distribution route. SALSA also expects finished-product testing programmes to include product at the end of shelf life, which is precisely the sample most people skip.
FIFO is not FEFO, and the difference is money
This is the part that quietly costs manufacturers the most, because it looks like it is already handled. FIFO uses the oldest received stock first. FEFO uses the stock with the earliest expiry first. They only coincide when every delivery arrives with the same remaining life, which is almost never true.
Rotate by receipt date and you reach for Batch A, leaving Batch B to expire in stock. Rotate by best-before and you use Batch B first and lose nothing. Same shelf, same data, two very different write-off figures at year end.
Getting this right is also a documented requirement, not just good housekeeping: stock rotation and use-by control are exactly what an auditor means when they ask how you manage rotation.
Date codes only work if they point somewhere
A date on a pack answers one question. A date tied to a batch answers all the others: which run, which ingredient lots, which customers. If a complaint arrives about a product tasting off at eight months, the useful response is to pull that batch's record, its test results and its despatch list, not to search a spreadsheet for what was running that week.
Two things belong alongside the date. First, the batch or lot reference, so the code is traceable. Second, the storage conditions the life depends on: a shelf life validated chilled means nothing on a pack that doesn't say keep refrigerated.
A short checklist
- Decide use-by or best-before from the hazard analysis, and write down why.
- Hold a test plan per product: test types, frequency, pass criteria, target life.
- Test in the real pack and real storage conditions, including at end of life.
- Record pH and water activity ranges, and re-check them after any reformulation.
- Review annually, and on any change of recipe, supplier, packaging or distribution.
- Rotate stock by expiry date, not receipt date, and let the system pick the batch.
- Make every date code traceable to a batch, with storage conditions declared on pack.
The bottom line
Shelf life is where food safety and margin meet. Too short and you throw away good product and lose listings; too long and you are one complaint away from a problem you cannot evidence your way out of. The manufacturers who handle it well are not testing more than everyone else. They are keeping the test plan, the results and the rotation rule in one place, so the number on the pack is a conclusion rather than a habit.
Frequently asked questions
What is the difference between use-by and best-before?
Use-by is about safety and is required on highly perishable food, selling past it is illegal. Best-before is about quality: the food may be less good afterwards but is not unsafe and can still legally be sold. The choice should follow from your hazard analysis.
How do you validate a shelf life?
With a documented test plan per product covering microbiological testing, sensory assessment and intrinsic factors such as pH and water activity, sampled across the intended life including at the end of it. Where pathogen growth is credible, challenge testing or predictive modelling may be needed. The dated results are the record an auditor asks for.
How often should shelf life be revalidated?
Reviewed annually, and whenever something material changes, recipe, supplier, packaging, storage or process. SALSA requires shelf life to be validated with records retained, and finished-product testing to include product at the end of its shelf life.
What is the difference between FIFO and FEFO?
FIFO uses the oldest received stock first; FEFO uses the earliest-expiring stock first. They are not the same, because a delivery received today can have a shorter remaining life than one received last month. Rotating by receipt date is a common cause of avoidable waste.
What should a date code include besides the date?
A traceable batch or lot reference, so a complaint or shelf-life query can be tied to a specific production run, its ingredient batches and its customers. Storage conditions must also be declared where the shelf life depends on them.
Rotate by expiry, not by habit.
See how Prodara handles shelf-life validation and FEFO allocation on the same batch numbers.