What do best by, sell by, and use by dates actually mean?

With the single exception of infant formula, food date labeling is not federally regulated in the United States, and the dates are chosen by manufacturers to indicate peak quality rather than safety. Best if used by indicates when flavor and texture are optimal. Sell by is inventory guidance for the retailer and says nothing to the consumer about safety. Use by is the closest to a safety indication and is the one worth respecting on genuinely perishable items such as fresh meat, dairy, and prepared foods, while on shelf-stable products it still refers to quality.

The consequence of the confusion is substantial waste. USDA and industry research has attributed a significant share of household food waste to misinterpretation of date labels, with people discarding safe food on the date printed. Many products remain good well past their dates when stored properly: eggs for weeks past the carton date, unopened shelf-stable canned goods for years with quality declining slowly, dry pasta and rice for a very long time. The federal government and industry groups have pushed toward standardizing on two phrases, best if used by for quality and use by for the limited set of items where safety is implicated.

How to judge instead. Trust storage conditions and your senses for most foods: sour smell, off color, slimy texture, and mold are meaningful signals, while a date is not. The exceptions where you should not rely on senses are the ones that matter: Listeria grows at refrigerator temperatures without producing spoilage signs and is dangerous particularly for pregnant people and the immunocompromised, so deli meats, soft cheeses, and prepared refrigerated foods deserve more conservative treatment. Never taste to test suspect food. Discard any canned good that is bulging, leaking, or badly dented along a seam regardless of date, since those indicate potential botulism risk, which produces no smell or taste.