Once you open those products, though, there are a few things to keep in mind: Pastas and other flour-based dried products will diminish in flavor and texture the longer they’re exposed to air—and can even attract unwanted pests like pantry moths and rodents if left in their original containers at room temperature, Syers says. 

Here are some basic use-by guidelines for the most common wheat-based pantry products from FoodSafety.gov:

• Breadcrumbs: 12 months unopened; up to 6 months after opening 
• Cereal: 12 months unopened; 2 to 3 months after opening
• Pasta: 2 years unopened; up to 1 year after opening
• Flour: 12 months unopened; 6 to 8 months after opening
• Crackers: 8 months unopened; 1 month after opening
• Oats: 8 months unopened; 4 months after opening
• Quinoa: 2 to 3 years unopened; up to 6 months after opening

Dried and freeze-dried fruit

Dried fruits have a life span of six months unopened and just one month after opening. A trace amount of remaining moisture in products like these is the reason for their relatively short life span, Syers says. However, research shows that freeze-dried fruit, as long as it remains unactivated by liquid, can retain both its flavor and nutrient profile for a year or more—and possibly longer when stored at moderate temperatures, limited humidity, and in an airtight container. 

Condiments 

Although you may have mustard and ketchup taking up shelf space in your fridge, Dr. Amalaradjou says they don’t have to. “Because of [their] natural acidity, ketchup and mustard are shelf-stable.” However, she adds that even though they won’t technically go bad at room temperature, refrigerating after opening will maintain the quality of these ingredients longer.  

Although those condiments have long life spans, others—especially those that contain ingredients like eggs and cream, like mayonnaise and ranch dressing—have shorter lives: 

• Ketchup: 1 year unopened; 6 months refrigerated after opening
• Mustard: 2 years unopened; 1 year refrigerated after opening
• Hot sauce: up to 2 years unopened; 6 months opened and stored at room temperature; 1 to 2 years refrigerated after opening
• Vinegar: nearly indefinite unopened; 2 years stored at room temperature after opening
• Mayonnaise: 3 to 6 months unopened; 2 months refrigerated after opening
• Salad dressing: 10 to 12 months unopened; 1 to 3 months refrigerated after opening

Sugar and sweeteners

Syers says that you have a lot of leeway when it comes to the life span of sweeteners like sugar. Sugar can be safely consumed indefinitely, but it won’t taste as good (or function as well in your baking) after two years. Similarly, brown sugar, honey, and agave are all safe to eat virtually forever, but you will notice changes in taste and texture the older they get.

Pickled foods

Shelf-stable pickles should be eaten within one year from the date of purchase for the best quality and will last one to three months in the refrigerator after opening, according to Syers. He adds that other pickled foods and ingredients preserved in brine, like olives, peppers, or giardiniera, have similar life spans as well. 

Sweetened preserves

Thanks to the high amount of sugar that they contain, sweetened preserves like jelly, jam, and marmalade have an impressive shelf life of 6 to 18 months when unopened and 6 to 12 months if refrigerated after opening. Reduced-sugar varieties, though, may develop mold more quickly than their sweeter counterparts. 

Broths and stocks

“For quality, chicken or vegetable broth should be used by the date on the package and three to four days in the refrigerator if opened,” Syers explains. Dry bouillon cubes or powder will last quite a bit longer because the lack of moisture prevents pathogens from forming. He says that ingredients like this will last one year unopened and one year after opening before the flavor starts to diminish.  

Baking powder and soda 

Baking powder and soda can keep for a while, but hang on to them too long and you may notice some issues with baking, Syers says. If you keep them longer than the time frames listed below, your cakes and cookies may not rise as much—but, despite their diminished quality, they’re unlikely to cause any food safety problems, Syers adds.