Best Before and Use By Dates: When to Save and When to Chuck
When it comes to pushing the line of the best-before and use-by dates of foods, most kitchens and consumers at home find this to be a grey area. In all honesty, even experts cannot always agree if this is a solid line that should never be crossed or if it is acceptable to push the limits. Today, there is an increasing question about food security and the urgent need to prevent food wastage. Considering this, it becomes essential to understand exactly when to save food and when it must be discarded to prevent illness.
Unfortunately, in many countries, food labelling laws remain somewhat ambiguous. This allows manufacturers to use either dating convention without always clearly defining the technical meaning to the end user. To manage a safe kitchen, we must look at the science behind the label.
2.0 Best Before: A Measure of Quality
The best-before date is primarily a measure of quality. This refers to the taste, texture, aroma, and visual appearance of the food. These dates are specifically assigned to products that do not easily support the rapid growth of bacteria and other microorganisms.
Examples include ice cream, butter, bread, and various tinned or dried products. Consuming these items a day or two after the best-before date may result in a slightly stale taste or a change in texture, but it is unlikely to cause a microbiological infection. In these cases, the manufacturer is simply guaranteeing that the “peak” experience of the product occurs before that date.
3.0 Use-By Dates: A Scientific Deadline
Use-by dates are significantly different and far more critical. This date is a measure of suitability for human consumption and is determined on a strict scientific basis. You will find these dates on highly perishable, fresh, or ready-to-eat foods that support the growth of bacteria.
These dates are determined by what is called a shelf-life test. This involves laboratory microbiological testing to see how long it takes for populations of Listeria monocytogenes or Salmonella to reach dangerous levels. As bacteria proliferate, the food expires. These conditions support the growth of spoilage bacteria (which make food smell or look bad) but also pathogenic bacteria, which can make you severely ill without changing the smell or taste of the food at all.
4.0 The Impact of Temperature on Expiry
Determining these dates is both a science and an art. The temperature at which food is stored plays the most critical role in whether a use-by date remains accurate. Fresh foods must be kept between 4°C and 7°C to minimise the growth of Staphylococcus aureus and other pathogens.
Manufacturers cannot foresee if a consumer will leave milk on a hot counter or if a buffet will subject meat to the Danger Zone (20°C to 45°C). If food is temperature-abused, it will expire much faster than the date on the packet. Conversely, freezing a product before its use-by date can stop the “biological clock,” allowing it to last longer, provided it is handled correctly once defrosted.
5.0 Long versus Short Shelf-Life Logic
Best-before products usually have a long shelf-life and do not naturally support bacterial blooms. Because these dates are not “set in stone” regarding safety, stretching them by a few days is often a reasonable expectation for a healthy adult.
However, use-by dated foods typically have a short shelf-life of 3 to 7 days. There is a reasonable scientific expectation that the bacterial load will reach a tipping point exactly around the date shown. For these items, there is no “grey area”—the risk of food poisoning increases exponentially the moment the date passes.
6.0 Professional and Domestic Kitchen Standards
In a professional kitchen, you are the first point of accountability for food poisoning complaints. It is absolutely essential that all manufacturer dates are adhered to strictly. Furthermore, HFS 2026 standards dictate that any food prepared in-house—meaning items that have been mixed, chopped, or cooked—must only be kept for a maximum of 2 days from the date of preparation, regardless of the original ingredient dates.
At home, while you are not governed by the same food laws, you have a moral obligation to serve safe food to your family. While you can be a little more flexible with best-before dates on dried goods, use-by dates should be respected as a hard limit. Better meal planning is always a more responsible alternative to taking a risk with expired perishables.
Want to understand more about the invisible world of food spoilage? Read our article on how bacteria grow or explore our Food Safety Checklists to improve your kitchen’s storage systems.