How To Dehydrate Onions (with a dehydrator)

How to dehydrate onions for food storage and save money on buying dried onions and onion powder.

If the garden is bursting or you have bought a boat load of fresh onions on sale you can dry them at home in a food dehydrator.

You can stock the pantry with all the dried onion and use them for onion powder for the entire year.

You'll save money and stock the spice cabinet for months or years to come.

Dehydrated onions can also be rehydrated to cook with just like fresh onions or they can be ground into onion powder.

Ingredients

Fresh onions and water are all the ingredients you need along with a food dehydrator.

Fresh large white onions in a galvanized bucket.

large white or red onions
water to wash any dirt or bugs from the onions.

Step by step directions

Follow these easy step by step directions to dehydrate diced or onion flakes to use in your recipes or to grind into onion powder.

Step 1: Buy or harvest fresh onions from the garden.

Step 2: Wash the onions in cold water before peeling them.

Large peeled white onions in a white enamel colander.

Step 3: Cut the ends off the onions then slice into ¼ inch slices. Separate the onion slices into rings.

Large white onions cut into slices in a large stainless steal bowl.

Step 4: Chop the onion rings into a rough dice. The pieces should be ¼ to ½ inch pieces.

A large glass bowl filled with diced onions.

Step 5: Arrange the diced onions on dehydrator trays that have been lined with plastic tray liners.

Diced onions spread over a dehydrator tray.

Step 6: Fill all the dehydrator trays with the onion pieces. Place the trays on or in the dehydrator. Set the temperature to 125 F. degrees if you are using a dehydrator with a temperature control setting.

A round dehydrator tray filled with dried onion flakes.

Step 7: Allow the onions to dry until they are completely bone dry.

How can you tell if the dehydrated onions are done? Pick up a few of the largest thickest pieces and allow them to come to room temperature.

Press on the center to see if it feels dry. If it feels moist or mushy continue drying the onion for an hour or more.

If the pieces snap when you bend them or they have a dry paper like texture they are done.

Step 8: Allow the dried onion to cool to room temperature before storing in an air tight container.

Dried onion pieces in a green bowl cooling before storing.

Recipe FAQS

Below I have answered some common questions about dehydrating onions.

Do onions need to be blanched before dehydrating.

Onions are one of the few vegetables that do not need to be blanched before dehydrating.

Can you dehydrate frozen onion?

Want to skip the hassle of cutting and copping fresh onions to dehydrate them? You can buy frozen bags of onion and dehydrate them instead.

How long do dehydrated onions last?

The shelf life of dehydrated onions can be anywhere from 6 months to 10 or 15 years if stored in an air tight container with a oxygen absorber in a cool dark place.

How to rehydrate dehydrated onions?

Measure the amount of onion you need into a small bowl. Pour hot water over the top to cover and allow the onion to absorb the water for up to an hour. Drain well and use as you would fresh onion.

Recipe Expert Tips

Below are more tips to help you succeed in dehydrating onions.

Blanching onions: onions are one of the few vegetables that do not need to be blanched before dehydrating. But if you would like to cut back on the odor of onions in your home while you are dehydrating a large amount of onions blanching will help with the odor.

The sharp eye burning fumes of cut fresh onions comes from a gas in raw fresh onions. Dipping sliced or chopped raw onion in boiling water removes some of the naturally occurring gas that causes the burning sensation to your eyes causing your eyes to tear.

If you plan to blanch the onion I suggest slicing the onion into rings that will be easier to dip and remove from the pot of boiling water. If you want to dehydrate minced onion or onion flakes cut them after blanching the onion rings.

Dehydrator temperature: If using a Excalibur or similar dehydrator with a temperature control all vegetables should be dehydrated at 125 F. degrees.
How long to dehydrate: How long to dehydrate onions will depend on a number of factors. The humidity in your home, the type of dehydrator you are using, the variety of onions and how you have cut the onions will all effect the amount of time it takes to dehydrate the onions until they are properly dried for storage.
Rehydrating dehydrated onions: Place the dried onion pieces into a bowl. Pour hot water over them and let sit for about an hour. The onions will rehydrate as they absorb the water. Strain the plump onion pieces before using.

Overhead photo of a small wooden bowl and spoon filled with dehydrated onion flakes.

Dehydrated onion uses

Rehydrate the dried onions and add use them just like you would fresh onions to flavor your recipes.
Use a grinder to turn the dried onion pieces into homemade onion powder.
Add the dried onion flakes to a pot of soup or stew to add flavor.

Storing dehydrated foods

After all that hard work you put into dehydrating onions or any other dried fruits or vegetables you don't want them to get ruined by not storing them properly.

If you want the shelf life to be as long as possible you need to store them properly.

I like to store my dehydrated foods in mason jars that have been vacuumed sealed to remove all the air.

Below are a few other options you have to properly store your homemade dehydrated foods.

Always store your dehydrated food in a dark cool cabinet or away from direct sunlight.

Glass jars with tight fitting and air tight lids.
Mason jars that have been vacuumed sealed.
Mylar bags.
Zip topped bags.
Airtight plastic food grade containers.

More dehydrated food ideas

Save money and space by dehydrating fresh fruits and vegetables.