We’ve all heard tales of the Twinkie that would survive (as fresh as the day it was made) into the next millennium, but most food, fortunately, does not have quite so long a shelf life. Confused about what to keep and when to toss? Here, a guide to the lifespan of some of the foods currently sitting on your refrigerator or pantry shelves.

Ever wonder why that wonderful fresh loaf you bought at the bakery grows mold in a matter of days, while the grocery store variety can last for several weeks? The difference is preservatives, which can greatly extend the shelf life of mass-produced bread. But you also play a role in how long bread survives in your kitchen. “In order to lengthen the shelf-life of bread it should be stored in a reasonably air-tight container,” recommends Ira Allen, a spokesperson for the Food and Drug Administration (FDA). Humidity will also create a prime environment for bread to mold, so try to store bread in a dry place if possible.

When it comes to its edible lifespan, not all cheese is created equal. “Hard cheeses (like Parmigiano reggiano)  can literally last for years, while soft cheeses (like brie or goat cheese) will mold much sooner,” says Allen. That’s because of the difference in the amount of moisture in the cheese—ones with more moisture (soft cheeses) grow mold much faster than those with very little moisture content. Soft cheeses should be tossed when you see mold starting to grow, but hard cheeses can be salvaged. Allen recommends slicing away at least one inch around all sides of the moldy area to make the remaining cheese safe to eat. There are two good guidelines to follow when trying to decide if the milk in your fridge is spoiled. Check the date on the carton and give it a sniff. If it smells sour to your nose, chances are it won’t taste very good in your coffee or cereal. There’s no difference in the lifespan between organic and non-organic versions of milk, but the amount of fat in the milk can impact its shelf life. “Over time, the milk fat will become rancid, and since non-fat or skim milk has had all of the fat removed, it can last longer than whole milk,” says Allen.
Keeping eggs safe means keeping them cool. Make sure you purchase them from a refrigerated case and store them at home—in their carton—in the refrigerator. You can use the “best if used by” date stamped on the carton as your safe-eating guide, but as a general rule eggs should last for about three weeks after you bring them home.
If you buy your lunch meats freshly sliced from the deli counter, you want to make sure you eat them within three to five days (and keep them cool in the fridge during that time). An unopened package of turkey, ham, bologna, salami or other deli meats can be stored for up to two weeks. But once you break that factory seal, they still need to find their way onto a sandwich within three to five days.
Your jar will probably have a “best by” date stamped on it. Whether the jar is opened or remains sealed, it will taste best if you use it by that date. “Once the jar is opened and the product exposed to oxygen, the flavors in the oil may be affected,” says Allen. Again, the best approach is to follow your nose. If the oils separate and start to smell off, the mayonnaise is past its prime.
When you buy a head of lettuce at the store, it should keep, intact, for about two weeks. But once you open up the head and cut up the lettuce, it will start to spoil faster. “That’s because you’re exposing the interior of the lettuce,” says Allen. And that releases nutrients for bacteria to feed on, and causes leaves to brown due to being exposed to oxygen. Those leaf lettuces that are contained in special modified atmosphere packaging can last longer than a head you cut up because they are better protected from oxygen and bacteria exposure.
Fresh Meat and Poultry