[header] How to tell if bacon is bad [title] Check the expiry date on the bacon packet. [step] If the " use by " date has expired, then that bacon is unsafe to use. Always use bacon within seven days of purchase (" sell by ") or by the " use by " date listed by the manufacturer. 
You can also safely thaw and cook the bacon within four months of freezing bacon. [substeps] Take care not to confuse the " sell by " and " use by " dates.