Does corn flour go bad?

In this brief guide, we will answer the query, “Does corn flour go bad?” and will discuss how to increase the shelf life of cornflour.

Does corn flour go bad?

Yes, cornflour can go bad. Flaxseed (corn flour seeds) has a limited shelf life because of how it is kept and the best before date on the bag. Preventing foodborne disease is as simple as following good hygiene and food safety practices. When whole corn flour goes bad, it develops a rancid odor, which makes it easy to identify. Because whole corn flour is produced from the corn grains, it contains some of the grain’s essential oils, which deteriorate over time and give off a rancid odor when baked goods are exposed to air.

International analysts have found that the global market of corn deep processing will grow by 25 % and reach 1.191 bln tons by 2026. The impetus for production growth will be an increase in the world’s population by 3 bln people by 2050; in addition, the demand for corn products in Asian countries will increase by 53 % till 2026 compared with similar indicators in 2016. Also, the consumption of corn products in North and South America will increase by 38 % by 2026 (1).

Corn Flour: What Is It?

Whole dried maize kernels are processed to make corn flour, which is a kind of flour. Whole grain flour is defined as having the hull, germ, and endosperm of the grain still in it, as opposed to refined flour. However, the color of cornflour may vary depending on the type of maize used, from yellow to white or even blue. It has a fine and silky texture, comparable to whole wheat flour in terms of appearance.

In the food industries, corn is processed through the so-called dry and wet-milling. In dry-milling, the separation of the endosperm, pericarp, and germ occurs. Thus, the endosperm is intended for the production of the flour, the pericarp for the high fiber flours production, and the germ for oil extraction, resulting in defatted bran. Also, corn can be ground without this separation, resulting in whole flours. The wet-milling is primarily intended for starch extraction. In wet-milling, the germ is also separated and destined for the extraction of oil, resulting in the corn bran that is destined for animal feed (4).

Corn flour, like other flours, provides baked products and other meal structure. To give it form, it’s often mixed with a binder, such as eggs. Raw corn flour has a bland taste, but when baked, fried, or grilled, its earthy, sweet flavor comes through. Corn flour may be used in a wide variety of dishes, including bread, muffins, waffles, pancakes, battered and fried meals, blinis, and more.

Making Corn Flour at Home

It may seem difficult to make corn flour at home, but it’s very simple. There’s just one thing you’ll need to prepare this dish: dried corn. Traditional techniques call for drying corn on the cob, separating it from the stalk, and then grinding it, but there’s an easier approach. Maize food products can be processed at home on a small local scale as well as on a larger industrial scale, transforming the raw material into food products (3).

Popcorn kernels and a powerful blender like a Vitamix or Blendtec are all you need. Blenders with strong enough blades will be able to process the kernels. You may use your normal blender container and blades, but if you want to grind entire grains, you may want to invest in a dry-grains container.

Just fill the blender container halfway with the kernels and mix until smooth. High-speed blending until a fine powder is formed from the kernels. Refrigerate and use within a few days if stored in an airtight container or plastic zip-top bag. Alternatively, you may keep the flour in a zip-top freezer bag for up to six months in the freezer.

Sign of bad cornflour

Preventing foodborne disease is as simple as following good hygiene and food safety practices. When whole corn flour goes bad, it develops a rancid odor, which makes it easy to identify. Because whole corn flour is produced from the corn grains, it contains some of the grain’s essential oils, which deteriorate over time and give off a rancid odor when baked goods are exposed to air.

For a number of products, lipid oxidation is the most important food quality parameter for nutritional, shelf life, and safety implications. Lipid oxidation may be detected by typical rancid aroma. Lipid peroxidation, or autoxidation of living systems, has been implicated in DNA and protein modification, radiation damage, aging and age pigment formation, modification of membrane structure, tumor initiation, and in deposition of arterial plaque associated with low density lipoprotein modification (2).

The most frequent cause of spoilage in flour is the presence of weevils (a minuscule insect) that live in the bag and deposit their eggs there. To get rid of weevils, some recommend freezing the flour bag for 48 hours, but it’s better to toss it in the garbage right away. After that, you should sterilize the whole pantry, since there’s a good possibility the weevils came from or went to another part of it.

If your flour has gone bad, you may find an alternative on our page of substitutions. Remember to practice food safety and consume your meals before their shelf life has ended since there are specific health hazards connected with rotting foods.

How should flour be stored to get the most use out of it?

A plastic bag or airtight container are both good options for storing flour since they keep it fresh. Keeping them cold and dry extends the life of any kind of variety. Because the powder readily absorbs smells and chemicals from its surroundings, it should be stored in a vapor-proof container. The contents of the bag may be put into another airtight container after they’ve been unzipped. 

Studies show that temperature and moisture are the critical points determining the shelf life of corn flour. When the humidity of the environment increases, the shelf life of flour decreases, and the same occurs for temperature. By increased temperatures, the deterioration rate increases. The degradation of lipids due to hydrolysis may produce free fatty acids, which can act as a substrate for further oxidation and impart off flavors during subsequent storage (5).

The original bag may also be protected by being put inside of a second plastic bag. Whole grain flour’s shelf life may be prolonged by several months by keeping it in the refrigerator or freezer, however white flour’s shelf life relies on it being fully dry, therefore this is not advised, due to the tendency of the flour to absorb moisture (5). Proper food storage has several advantages, including improved health, lower food prices, and less waste.

Is it possible to become ill from eating flour that has gone bad?

Flour indeed has a rather long shelf life, but even so, eventually, it will go bad. Your delicious baked products will be ruined if they are prepared with rancid, musty flour. It’s possible that preparing food using outdated flour may make you sick due to the dangerous moldsbacteria that are there.

Fumonisins are a group of structurally related mycotoxins primarily produced by F. verticillioides and F. proliferatum; fumonisin B1 and B2 are the most abundant and are often found as contaminants in corn products. The toxins are associated with a wide range of toxic effects, and the liver and kidney are the most sensitive target organs. FB1 is the most toxic fumonisin, related to an inhibition of sphingolipid synthesis and increased risk of esophageal cancer in humans (6).

To check out the cornflour recipes, click here 

Other FAQs about Cornflour that you may be interested in.

What is the difference between cornflour and corn meal?


In this brief guide, we answered the query, “Does corn flour go bad?” and discussed how to increase the shelf life of cornflour.


  1. Tanklevska, Natalia, et al. World corn market: analysis, trends and prospects of its deep processing. Agric Res Econo Int Scient E-J, 2020, 6, 96-111.
  2. López-Duarte, Ana Lilia, and Reyna Luz Vidal-Quintanar. Oxidation of linoleic acid as a marker for shelf life of corn flour. Food Chem, 2009, 114, 478-483.
  3. Gwirtz, Jeffrey A., and Maria Nieves Garcia‐Casal. Processing maize flour and corn meal food products. Ann New York Acad Sci, 2014, 1312, 66-75.
  4. da Silva Timm, N., Coradi, P.C., dos Santos Bilhalva, N. et al. Effects of corn drying and storage conditions on flour, starch, feed, and ethanol production: a review. J Food Sci Technol, 2022. 
  5. Deepa, C., and H. Umesh Hebbar. Effect of micronization of maize grains on shelf‐life of flour. J Food Process Preserv, 2017, 41, e13195.
  6. Torović, Ljilja. Fusarium toxins in corn food products: A survey of the Serbian retail market. Food Addit Cont A, 2018, 35, 1596-1609.