Does Flour Expire? We Decided to Find Out

Have you ever wondered, "Does flour expire?" The short answer is yes. The long answer is a little more complicated.

Most of my professional chef career was spent in a farm-to-table kitchen that made almost everything from scratch. Two of our big ticket items were homemade pizza and pasta, so you can imagine that we went through a lot of flour! Stacks upon stacks of 50-pound bags lined the walls of our dry storage area, and we used flour so frequently that we never had to worry about it going bad.

As a home cook, you may find yourself asking, “does flour expire?”, especially if you pick up one of those 25-pound bulk deals at Costco. The short answer is yes, flour does go bad; but the long answer depends on the type of flour and how it’s stored.

Does Flour Go Bad?

Flour seems like one of those pantry items with an unlimited shelf life, but it does actually expire. All flour has a printed “best by” or “best if used by” date somewhere on the package. This date reflects the manufacturer’s suggested date for best quality. You can generally use flour for four to six months past this date, depending on how you’ve stored the flour —more on that in a moment!

How Long Does Flour Last?

Each type of flour has a different expiration date. For example, whole grain flour contains more oils than refined flour (like all-purpose flour), and gluten-free flours containing nuts are high in fat, so these flours can become rancid more quickly. Unless the best by date is within a few months of purchasing, we prefer to assume the clock starts ticking based on the purchase date instead of the printed best by date. Storage conditions are stable and predictable in a warehouse, but things vary once you bring the flour home and open the bag. Once the flour is exposed to air, it begins to oxidize and can slowly go bad.

Here’s a general rule of thumb about how long each type of flour will last after the purchase date. You can extend the dates below by roughly double by storing flour in the freezer.

  • All-purpose flour: About 1 year
  • Bread flour: 4 to 6 months
  • Cake flour: 6 months to 1 year
  • Nut flours (almond, coconut, etc.): 3 to 6 months
  • Pastry flour: 6 months to 1 year
  • Self-rising flour: 4 to 6 months
  • Whole wheat flour: 3 to 6 months

How Can You Tell If Flour Is Bad?

Flour should be white or cream-colored with a smooth, dry texture and a neutral aroma. It can have some lumps, but they should dissolve easily when the flour passes through your fingers. If flour is gray or yellowing, contains lumps due to moisture or smells musty, sour or generally unpleasant, it’s time to toss it. Flour with signs of insect or rodent infestation (i.e. little brown or black spots in the flour or holes and tears in the bag) should be thrown away regardless of the condition of the flour. (This is how to get rid of common pantry pests.)

Can You Use Expired Flour?

Can you use flour past its best by date? Probably. If it doesn’t show any signs of deterioration, and it’s been stored in a cool, dry place, it should be fine for a few months past the printed date. Most of the time, using expired flour won’t make you sick. But there is a small chance rancid flour can cause symptoms of food poisoning, like stomach pain, vomiting or diarrhea, so it’s definitely one of those items you don’t want to leave in the pantry too long.

Which brings us to a more important question: Should you use flour once it’s expired? If you’re storing flour in the freezer, it’s likely okay. Otherwise, probably not. Expired flour won’t have the same quality in flavor and texture, so your recipe won’t turn out the same. When it comes to self-rising flour, which contains baking powder, expired flour will create baked goods that don’t rise.

If you feel bad throwing away expired flour, toss it into the compost bin. It does take a while to compost, so you’ll want to mix in plenty of green materials like fruits and vegetables. You can also use it as an insect repellant—ants won’t cross a line of flour—or sprinkle it on a dry, clean cloth and use it to polish your stainless steel appliances.

How to Store Flour

Store flour in an airtight container in a cool, dry place. Keep in mind that flour will last longer when stored at cooler temperatures. For example, all-purpose flour lasts about a year in 70°F storage temperatures, or two years if stored at 40° or lower. If you pick up a bulk bag of flour, consider storing a small amount in the pantry for everyday use and the rest of the bag in the freezer.

Need to use up your whole wheat flour before it goes bad? Try these baking recipes!

Lindsay D. Mattison
Lindsay is a professional chef, recipe developer, writer and developmental editor. After years of working in restaurant kitchens, she turned to writing to share her skills and experience with home cooks and food enthusiasts. She's passionate about using local, organic ingredients and teaching others how to incorporate seasonal food into their diet. Lindsay still cooks professionally for pop-up events, writes for several publications and is the co-author of two books about Ayurveda.