How to Dehydrate Onions?


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Were you aware that by dehydrating onions, their lifespan can be extended and it can present a more imaginative method to incorporate them into your meals? Dehydration, due to its easy-to-follow process, is the most long-standing method of preserving food.

The National Center for Home Food Preservation recommends dehydration as a suitable method for preserving onions. Dehydrated onions are safe to eat if kept in a cold dark place for two years. It doesn’t matter if they are minced dried onions, dried onion flakes, or onion powder.

This article discussed how to dehydrate onions at home and preserve them for use in your favorite recipes on the go. Read on to learn how to save a bumper onion harvest from getting spoiled before you can use them.

How Can You Use Dehydrated Onions?

Sometimes you might lack time to peel, chop, or dice onions for use in the kitchen. The perfect alternative is to use dried onion flakes in place of fresh onions. Whether you have homemade onion powder, dried minced onions, or dried onion flakes, here are some ways to use them in the kitchen:

1. Rehydrate Dry Onions

Before using dried onion flakes, you can rehydrate them and use them like raw onions in salads and cooked food. You can rehydrate dry onions by soaking one part of minced dried onions into two parts of fresh warm water. Wait for 20 minutes or until the onions become soft. Then use them in your favorite recipe.

2. Mix Onion Powder with Dry Herbs

Powdered onion can easily mix and combine dry herbs to provide a richer flavor. So, before using onion powder, you can combine it with spices and dried herbs. The result is a shelf-stable mix like taco seasoning, DIY herb blends, and rub mixes.

3. Add Dried Onions to Food

If you lack time to prepare anything special, add dried onion flakes directly to simmer stews and soups. The onions will reconstitute and add onion flavor to your favorite recipe as the liquid keeps boiling.

Why Should You Dehydrate Onions?

As you learn how to dehydrate onions, it’s also essential to ask you why it is necessary. For example, one of the reasons for dring onions is to keep their flavor fresh.

It works better than canning or freezing, which tends to alter the flavor of the onions. There is no need to worry about the onions getting spoiled or having a stale taste that could spoil your soup or broth.

Besides, dehydrating onions yourself is cheaper, especially if you grow onions in your garden or buy onions in bulk. In the end, you’ll save a lot of money compared to having to buy onions in small jars or packets of dried onions throughout the year.

How to Dehydrate Onions – Useful Tips

Did you know that dehydrating onions is the easiest way to preserve them? When dehydrated, onions lose moisture have a longer shelf-life when stored at room temperature.

Besides, dried food occupies less space in storage and is easy to reconstitute without losing flavor. Here are some valuable tips for getting onion dehydrated:

1. Use a Food Hydrator Instead of an Oven

A food dehydrator is much better than an oven when drying onions. You can set the onions to start drying and forget with a dehydrator.

There’s no stirring or fussing over how hot you need the oven to be. Besides, a food dryer presents zero risk of burning the onions, ensuring consistent drying.

Unlike the oven, the dehydrator also allows you to dry the onions while preserving their nutritional value.

When drying onions, you should avoid exposing them to extremely high temperatures. The heat can reduce the ability of the onions to boost your immunity and reduce inflammation.

2. Dehydrate Onions Outside the House

Drying onions have a strong smell, which can linger indoors for a long time. So, place the dehydrator on the porch, shed, or garage with the door open. Don’t forget that the smell of onions can also linger on the dehydrator trays.

Remove the odor by washing the trays in warm, soapy water. Rub the trays with lemon juice and rinse after drying. If the smell doesn’t go away, repeat the process.

3. Cut Onions Evenly Before Drying

If you want to know how to dehydrate onions, start by cutting them evenly into small pieces. With that, you’ll produce even onion flakes.

If you have a large number of onions, use the slicer blade in the food processor to cut them quickly and evenly. Then, put the onions into wedges until they fit the feeder tube and use the slicing blade to process them.

4. Avoid Getting Teary Eyes While Cutting Onions

Cutting onions expose your eyes to volatile gases that can make you develop teary eyes. However, you can avoid exposing yourself to the gases through the following simple tips:

  • Wear Kitchen Goggles: A pair of kitchen goggles can protect your eyes from getting hurt by gas from the onions.
  • Sharpen Your Knife: Cut the onions with a sharp knife to avoid releasing too much of the gas. With that, you’ll have protection from teary eyes.
  • Remove Roots Last: Many of the enzymes causing teary eyes are found in the roots of the onions. Therefore, you should cut the roots last to release as few enzymes as possible.
  • Chill Onions: Before you can cut the onions, first refrigerate them. With that, you’ll reduce just how much gas gets released into the air.
  • Use Kitchen Appliances: Why would you insist on using a knife when you have a convenient food processor? Instead, use the food processor to quickly cut the onions into smaller pieces.

5. Keep Checking Jars for Signs of Moisture

Dehydrated onions should get stored in airtight jars. However, storage shouldn’t end once you have transferred onions into the jars.

A few days after packing the onions, check for signs of moisture. If you see any traces of moisture, likely, the onions aren’t dry enough.

Semi-dry onions can develop mold and cause serious health problems. Therefore, you should process the onions using the dehydrator once again.

How to Dehydrate Onions in Simple Steps

It’s possible to dehydrate any fresh onion, whether white, yellow, or red. When cutting onions with your hands, wear gloves and eye protector goggles to ward off harsh gases. Here is a step-by-step process to help you dehydrate onions quickly.

What You Need:

  • Cutting board
  • Knife
  • Dehydrator
  • Spice grinder
  • Spice jars
  • Mesh strainer
  • Kitchen goggles
  • Gloves


Step 1: Prepare the Onions for Dehydration

After removing the dry skins, trim the fresh onions’ ends and slice them into small pieces. You can start by cutting the onions in half before slicing each half into pieces that are no more than ¼ inches. You may use a slicing blade to hasten the process.

Don’t worry about the shape of the onion flakes. What matters is that they have roughly the same size. Therefore, you can cut the onions into chunks, onion rings, or whatever shape you want. However, the pieces should be large enough to stay on dehydrator trays without falling through.

Step 2: Spreading Onions on Dehydrator Screens

Separate the onion pieces so that they stand alone. Spread the onions evenly on the dehydrator tray. Even though the onion pieces can touch, they shouldn’t overlap. If you make them overlap, they might not dry evenly.

Step 3: Dry the Onions

The ideal temperature for dehydrating onions is 125°F for three to nine hours drying time, depending on the onion pieces’ size and moisture content.

You can top the dehydrator and restart the process the following day if you wish. Keep rotating the trays to dry the onions evenly. Dehydrated onions are crisp, and pieces snap when you press against them.

Step 4: Package and Store the Onions

Allow the onions to cool after dehydrating. Use your hands or a mallet to crush the dried onions into flakes. Package the onions pieces into mason jars and keep them close to it to airtight.

Label the jars with the contents and date, and keep them in a cool, dark place like your spice cabinet. After a few days, check the jars for any signs of moisture accumulation. Dehydrating onions prolong their shelf-life without diminishing their flavor.

How to Dehydrate Onions and Make Powder

What You Need:

  • Onions
  • A dehydrator
  • A food processor
  • Storage containers


Step 1: Wash, Peel, and Cut the Onions

Peel the fresh onions and chop off the roots and green parts. After washing and removing excess dirt thinly slice the onions. After slicing the onions, separate the pieces to avoid having excessively thick layers. Remember, thinner onion pieces dry faster.

Make sure the onion slices are even and capable of drying together. You should have 1/8-inch or ¼-inch thick slices. Cut them into long, slender, or round pieces if you have green onions. While at it, reduce the tougher flowering stalks into small rings.

Step 2: Lay the Onion Slices on Dehydrator Trays

Lay the onion pieces evenly on dehydrating trays. Pack a large number of onion pieces on each tray. Even though the pieces can lay side-by-side, they cannot pile on top of each other. Instead, allow air circulation by leaving space in between the slices.

Step 3: Dehydrate the Onions

Load the onion-containing trays into the hydrator and turn it on. Setting the temperature around 125°F can dry adequately without cooking or denaturing antioxidants and enzymes. You want your dried onions to have the same nutrition value when you finally use them in a recipe.

Your dehydrator determines the onions’ drying time. Also important is how you arrange the pieces of onions on the trays. For example, it could take several days to dry the onions if you set the temperature setting at way too low.

Step 4: Check How Dry the Onions Are

Check that the onions are completely dry before removing them from the oven. But how do you know when the onions finally dry? Could you take a few pieces and break them? Dehydrated onions should crack and snap crisply. If they bend and maintain malleability, the onions aren’t dry enough.

Remember, onion powder prepared from less-dried pieces can clump up in the storage container and become moldy. If only a few pieces are dried, pull them out and leave the rest to continue drying.

Since the green parts dry faster than the rest, it would help if you kept them on separate trays. With that, you can remove and store them in airtight jars.

Step 5: Grind the Onions

Now is the time to prepare dried onion powder. For may use a coffee grinder, food processor, or blender. Put the dehydrated onion flakes in the instrument of your choice and turn it on. Grind the dried onions until you can no longer see any big chunk.

Step 6: Store the Onion Powder

Once you have ground the dried onions, transfer the powder to airtight half-pint or pint-size airtight containers, based on the quantity you’ve made. If you have old spice containers, repurpose them for storing the onion powder.

The reason for storing onion powder in airtight containers is to prolong its life for up to one year. It stays fresh without any degradation whatsoever and can add onion flavor to your food whenever you want it.

How to Make Dried Minced Onions

You can store the dehydrated onion pieces in their current sizes or reduce them to minced dried onions. You can make minced onions using a coffee grinder, spice grinder, or blender.

Put some dehydrated onions in the food grinder powder. Once you have placed the dried onions in the bowl, turn the device on and grind until you have pretty fine flakes.

Use a strainer to sift the more significant parts from the fine ones. Treat the fine particles as onion powder and the coarse particles as minced dried onions. Take a mason jar and pack the refined powder in it. Do the same for the minced onions.


Dehydrating onion is a straightforward process that anyone should do without trouble. Once you have prepared fresh onions, put them on trays. Slot the trays into the dehydrator and turn it on. Allow the drying time to lapse and remove the trays from the dehydrator.

Pack the dehydrated onions in jars and keep them in a dark, cool place. Avoid keeping the onions in direct sunlight since that can make the onions deteriorate.

Dehydrated onions can add flavor to many of your recipes. When adding them to food, you can add the onion flakes powder or rehydrate them before using them. Don’t hesitate to dehydrate onions at home.









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