Does Onion Powder Go Bad

In this brief article, we will answer the question, “does onion powder go bad?”. We will also tell you how to properly store onion powder, how to tell if it’s gone bad, and some facts about how onion powder is made.

Does Onion Powder Go Bad?

Rather than a straight yes or no, the answer to this question depends mainly on how you store the onion powder. Spices are hygroscopic in nature, because they are very sensitive to moisture. If they absorb too much moisture, they can cause caking, decolonization, hydrolytic rancidity, mold growth, and insects. Furthermore, heat, light, inadequate packing, and environmental factors are caused by the deterioration of fragrance and flavor components in spices during storage intervals (2).

According to the US Department of Agriculture (1), Properly stored commercial onion powder can usually last for as long as three to four years at room temperature, while homemade onion powder can last for up to a year if refrigerated. To further extend its shelf life, onion powder should be stored in a cool, dark place, away from moisture, humidity, heat, and direct sunlight. 

If you’ve bought onion powder in bulk and want to extend its shelf life and retain its flavor and potency, make sure you store it in airtight containers with secured lids.

Can You Use Onion Powder After Its Expiration Date?

Yes. If onion powder has been stored properly, the packaging is undamaged, and there are no apparent signs of spoilage, you can use it past its expiration date. 

Commercially available onion powders generally have a “Best Before”, “Best By”, or “Best if Used By” date. But remember that is not a safety date; it is an estimate by the manufacturer of how long the powder retains its peak quality.

So onion powder will not spoil after its expiry date, if it is unopened – it will simply lose some of its original potency and flavor and can still be used. However, spice powders containing highly volatile sulfur compounds, such as onion and garlic, require special protection to prevent flavor loss or absorption. The essential oil components found naturally in most spices are oxidized by oxygen in the air, resulting in off flavors, especially at high storage temperatures (2).

How Can You Tell If Onion Powder Is Spoiled? 

To test whether onion powder has spoiled, always rely on your sense of sight, smell, and taste.

Simply rub a small quantity of the onion powder in your hand to taste it. If it still has that pungent flavor and doesn’t taste bland or off, it’s good to go. Similarly, if its aroma is strong and on point, you can still use it.

As for sight, onion powder is light-shaded, fresh off-white with a red undertone. If the powder has changed color (looks darker than usual) or has whitish specks on it, it has possibly been exposed to moisture and is growing mold. In the latter’s case, you should immediately discard it.

Also, if you see insects or larvae crawling inside the onion powder, we don’t need to tell you to throw it away right away!

Is Onion Powder Made Using Real Onions?

Onion powder is made from air-drying, dehydrating, or freeze-drying onions followed by crushing them to either a flaky consistency or a  powdered product. Conventional air drying is one of the most frequently used operations for garlic dehydration. The drying method can significantly influence the physical, chemical and organoleptic characteristics of onion powder prepared with various drying methods viz., sun drying, hot air drying, freeze-drying and spray drying (4).

The more fine and dehydrated the product, the more concentrated and potent it will be. And similar to fresh onions, the flavor of onion powder differs as well, depending on the processing and manufacturing process. The packaging material for spice packaging should be sterilized and standard so as to reduce contamination during storage (2).

Why Does Onion Powder Harden?

The primary reason why onion powder becomes hard is that it absorbs moisture. Onion powders are dehydrated with as much as 96 percent of their water content removed. So, when water is reabsorbed by them, it tends to harden or clump.

Garlic powder is an amorphous powder and contains from the onion carbohydrates hydroxyl molecules which can bind to water. As it absorbs moisture, the formation of liquid bridges and solid bridges between particles occur, which cause it to undergo a glass transition to become rubbery. Because of this, powders begin to stick and to cake (3).

However, this does not necessarily mean that the powder isn’t good for use; it’s consistency and potency may have been somewhat compromised but it will not be classified as spoiled and can still be used for cooking. 

Unless there is too much hardening or clumping, along with a darkening in color that could also indicate bacterial growth, you can use the powder. 

How Can You Renew Onion Powder?

If your onion powder has absorbed moisture and changed consistency, add around six to 10 grams of uncooked white rice to the container it is stored in. Rice helps absorb excess moisture and will reduce further clumping. Because of its composition – of carbohydrate monomers attached in a long polymeric chain – rice and other grains are highly hydrophilic, that is, they tend to pull the water from the environment.

Can You Refrigerate Onion Powder?

Yes. As mentioned, homemade onion powder lasts for about a year – 8 months tops – so placing it in a ziplock bag or airtight jar and refrigerating it is the best method to enhance its longevity.

As for commercial varieties, you may or may not keep it in the refrigerator. Commercial onion powder contains preservatives that extend its shelf life considerably. 

Moreover, onion powder can also be frozen.  A study evaluating the influence of the storage temperatures on the quality of garlic powder demonstrated that storage at -10°C could better maintain the quality of the garlic powder during storage compared with the storage at 4°C and at room temperature. That can be attributed to onion powder (4).


In this brief article, we answered the question, “does onion powder go bad?”. We also told you how to properly store onion powder, how to tell if it’s gone bad, and some facts about how onion powder is made.

If you have any more questions or comments please let us know.



(2) Ahmad, Rabia Shabir, et al. Introductory Chapter: Herbs and Spices-An Overview. Herbs and Spices-New Processing Technologies, 2021.

(3) Grant, Lenese D., and Leonard N. Bell. Physical and chemical stability of tagatose powder. J food sci, 2012, 77, C308-C313.

(4) Madhu, Bogala, V. D. Mudgal, and P. S. Champawat. Influence of the packaging material and storage temperature on the shelf life of garlic powder. J food sci technol, 2021, 58, 4333-4343.