If they develop a sour smell, an off color, or begin to curdle, discard them. These products typically last about one week after opening.
Raw milk, which has not been pasteurized to destroy harmful bacteria such as Salmonella, E. coli, Listeria, and Campylobacter, is not considered safe to drink.
Eggs
Federal regulations do not require eggs to carry either a sell-by or use-by date, although some states do.
Eggs actually have a shelf life of three to five weeks.
“Even if the sell-by date has passed, they’re still safe to eat if they’ve been refrigerated at 40°F (4°C) or below,” says Isabel Maples.
However, throw away any cracked eggs because they may be contaminated with Salmonella.
Baby Formula
“This is the most important item on the list,” says Schaffner.
Formula may be the sole source of nutrition for infants. Manufacturers guarantee its nutrient content only until the use-by date. Feeding expired formula may result in inadequate nutrition, so always discard formula after the use-by date.
Deli Meat
Unless you’re buying unopened, factory-sealed deli meat, sliced deli meats typically last only three to five days.
Don’t wait until they become slimy or develop an unpleasant odor. Deli meats can harbor Listeria, which grows even in refrigerator temperatures and can cause serious illness, particularly in pregnant women.
Garlic in Oil
Commercially prepared chopped or minced garlic packed in oil can last 8–12 months unopened in the pantry and about one month after opening if refrigerated.
Homemade garlic stored in oil should be avoided because it carries a high risk of botulism. Garlic naturally contains bacterial spores from the soil, and the oxygen-free environment created by oil allows those spores to grow.
Canned Goods
Canned foods often remain safe long after their sell-by date, provided the can is not damaged.
High-acid foods (such as tomatoes or pineapple): about one year beyond the best-by date.
Low-acid foods (such as beans or corn): up to five years.
Discard any cans that are swollen, leaking, rusted, or badly dented.
Leftovers
Most leftovers should be eaten within three to four days.
After that, the risk of food poisoning increases.
Refrigerate or freeze leftovers within two hours of cooking. Divide large dishes, soups, or casseroles into smaller portions so they cool more quickly.
Prepackaged Lettuce
Use prepackaged lettuce within a few days of purchase.
If unopened, its quality declines after the best-by date.
Throw away the entire bag if any leaves become slimy.
If the package says “pre-washed,” “triple-washed,” or “ready to eat,” there’s no need to wash it again. Doing so may actually increase the risk of cross-contamination.
Head Lettuce and Cabbage
Head lettuce usually lasts about five days in the refrigerator. Keep it dry because moisture speeds spoilage.
“Leafy greens account for about half of food safety outbreaks involving produce,” says Maples.
Throw away the entire head if it becomes slimy.
Cabbage can last for several months. Simply remove the outer leaves if they become soft.
Cooking Oil
Most cooking oils last about one year unopened and around six months after opening.
Store oils away from heat and light. Once they develop a rancid or bitter smell or taste, discard them.
Hard Cheese
Hard cheeses such as Parmesan and Romano contain very little moisture and can remain safe for months after their sell-by date.
If mold develops, cut away the mold and at least one inch (2.5 cm) around it before using the remaining cheese.
Semi-Firm Cheese
Cheddar, Gouda, Swiss, and other semi-firm cheeses can be stored for up to six months unopened or three to four weeks after opening.
Because these cheeses contain less moisture than soft cheeses, mold spreads more slowly. If mold appears, cut away the mold plus at least one inch (2.5 cm) around it before eating the rest, says Maples.
