Here’s Why Your Flour Smells Like Crayons, According to the Experts at King Arthur

Flour is ubiquitous in the kitchen, especially if you’re a baker. And if you’re anything like me, you might own several bags of flour for different reasons. Maybe some “00” Caputo flour for pizza, whole wheat flour for loaves, and of course, all-purpose flour.

If I don’t go through one of them fast enough, it can be tough to remember when I bought it. Of course, the best-by date is a good way to check. But if your flour is on the border or past the best-by date, how does a home cook know when flour has gone bad?

Like milk or like meat, there’s an easy way to check if flour is still safe to use: Give it the smell test. If there is a funky smell coming from your flour, it’s probably gone bad. But the smell can vary depending on the type of flour you have.

What Makes Flour Smell Like Crayons?

We asked the experts at King Arthur Baking about the signs of sour flour, and they gave some great insights.

Flour generally has a neutral smell, and should not smell “off.” White flour (a.k.a. all-purpose flour) can be a little harder to gauge, but it will have a cardboard-like smell if it’s gone bad. “It may have a general ‘stale’ aroma,” says Jonathan Brasil, Research and Development Specialist at King Arthur Baking.

“Whole wheat will smell a little like crayons, if you can believe it. Mostly due to the fat in the flour becoming rancid,” says Jonathan. “Your best bet is to use your flour by the best-by date.”

Whole wheat flour has a small amount of fat that, over a long enough period of time, can spoil. Whole wheat flour has a small amount of fat that, over a long enough period of time, can spoil. And when it spoils, it can take on the smell of crayons. 

This is why whole wheat flour should be stored in the refrigerator or freezer. At room temperature or a cold, dark cabinet, whole wheat flour can last about one to three months. That number increases to six months in the fridge and up to a year in the freezer.

Alternative flours, like almond or other nut flours, also benefit from the smell test. If they smell rancid or sour, it’s probably best not to use them. Use your eyes as well: If you notice any dark specs, clumps that don’t break apart, or a change in color in any of your flours, it’s best to open a new bag.

If you’re interested in the best ways to store flour, King Arthur, along with Gold Medal and Pillsbury, answered that exact question.