“Use by” and “best before” can look similar on a package, but they do not communicate the same thing. A use-by date applies to foods that are highly perishable from a microbiological point of view and marks a safety limit. A best-before date indicates the period during which a food retains its specific properties when stored correctly.
The difference at a glance
| Use by | Best before | |
|---|---|---|
| Main question | Safety | Quality and durability |
| Used for | Highly microbiologically perishable foods | Foods that may lose quality before necessarily becoming unsafe |
| After the date | Do not consume | May still be suitable if stored correctly and the package is intact, although quality can decline |
What a use-by date means
A use-by date is used where, after a relatively short period, a food may constitute an immediate danger to human health from a microbiological point of view. It should therefore not be treated as a mere quality suggestion. Once it has passed, smell or appearance cannot establish that the food is safe.
What a best-before date means
A best-before date indicates how long a food retains its specific properties when properly stored. After that date, aroma, texture, colour, freshness or stability can deteriorate, but the date alone does not automatically make the food unsafe.
This does not mean foods last indefinitely. Storage instructions still matter, the package should be intact and the nature of the product matters. Oxidised oil, a damaged can or badly stored food may be unsuitable even before the printed date.
Storage conditions are part of the date
A date only makes sense alongside instructions such as “keep refrigerated”, “store in a cool dry place” or “once opened, consume within…”. If the cold chain is broken or the food is stored incorrectly, the printed date is not an independent guarantee.
What changes after opening
The printed date normally relates to an unopened product stored as instructed. Opening can introduce oxygen, moisture or microorganisms and change the food environment. That is why after-opening instructions matter more in practice than the fact that the printed date may still be months away.
Can smell, colour or taste decide safety?
No. Sensory checks can reveal some quality deterioration, but they cannot prove the absence of dangerous microorganisms. This is especially important for use-by foods. For best-before foods, appearance and smell can help assess quality together with packaging and storage, but they do not replace product-specific safety rules.
Different foods, different deterioration problems
Our guide to how long preserves last focuses on shelf-stable packaging and spoilage signs; whether EVOO expires and how it deteriorates is mainly about oxidation and loss of quality; and how to assess fresh meat condition addresses a much more perishable product. The presence of a date does not make these the same problem.
If a food is close to its date
Plan consumption, freeze only when appropriate and before the relevant safety limit, and follow the manufacturer’s specific instructions. A best-before food need not automatically be thrown away the day after its date; a food past its use-by date should not be “rescued” simply by cooking it.
The simple rule
Use by: safety; do not consume after the date. Best before: minimum quality; interpret it together with storage and package condition. In either case, swollen, leaking or damaged packaging or unsafe storage conditions override any reassurance from the printed date.
