There’s not much mystery over whether the milk has gone bad, you just smell it to check. But you can’t exactly sniff test dry goods like sugar or baking soda.

So… do baking ingredients expire? Not exactly.

The USDA’s Food Safety and Inspection Service alongside the Food Marketing Institute and Cornell University maintains an online resource called Foodkeeper.

CNET did the homework, and searched out the best advice for dry goods.

Leaveners

Leavening agents can be perfectly safe to eat for a long time… but they may not work as expected if they’re old.

Baking powder and baking soda lose potency over time. The science of baking — exact measuring, sifting and allowing things to rest or rise — can be easily dismantled by a bad box of baking soda or baking powder, the agents of change in many recipes.

Baking powder has the shorter lifespan. Even unopened, it’s only good for eighteen months. Once you open a can, you need to use it or discard it within six months. Same with baking soda once it’s opened. A sealed box, however, can last up to three years.

Flour

Stored properly, flour is good for months. White flour has a slightly longer shelf life than whole wheat.

If you found bugs in your flour, it’s probably because the flour wasn’t stored properly. Flour should be stored in an airtight container and in the refrigerator to prevent infestations.

Under those conditions, wheat flour will last eight months, and white flour up to a year.

Sugar

Turns out sugar may be the one true immortal in your pantry.

Technically, sugar never spoils. While it’s recommended that granulated sugar be discarded after two years, chances are it will still serve its baking purpose even beyond that. The same guidelines apply to brown sugar and confectioner’s or powdered sugar.

 

Remember, though, that old advice is good advice… if you aren’t sure how old an ingredient actually is, you’re better off to just replace it.