You can’t see, smell, or taste the bacteria that can make you sick. To protect against food poisoning, toss out food after 3 to 4 days in the fridge or move it to the freezer. While frozen leftovers are safe for a long time, they lose flavor and texture after 3 to 4 months. Always use airtight packaging or containers, and write down the date. If you're in doubt about whether the food has gone bad, throw it out.