Asked by: Trevor Wooding, Snodland
Use-by dates only apply to perishable products such as dairy foods, vegetables and beer. To determine the dates, samples of the food are monitored in a microbiology lab, in similar packaging and environmental conditions to those of the retail outlet and the home. Food scientists then test the samples for traces of known pathogens. The use-by date is calculated according to the point where levels of the microbes start to exceed safe limits.