Sell by: Manufacturers put these dates on products so stores know how long to display a food. Never buy food if the sell-by date has expired but if you have it at home past the date, itâs probably ok. What really matters is if the food was properly stored and at the right temperature in the store and at home. The safest way to store food Regardless of the date on the package, if you take too long to bring the food home, or donât store it properly, it can still be unsafe to eat. Make the grocery store your last stop before heading home and use a cooler or thermal bag for cold and frozen items.