How to Make Homemade Onion Powder (Dehydrator or Oven)

Come learn how to make homemade onion powder in this quick step-by-step tutorial, including how to dehydrate onions in either the oven or in a food dehydrator. This is a fantastic way to preserve onions from the garden, or reduce waste when you have extra from the store! When dried and stored properly, onion powder will last over a year in your pantry.

Homemade onion powder is easy to make and incredibly fresh, delicious, and full of flavor. It knocks the sock off anything you’ll buy in the store! Sweet, herbaceous, and versatile, it adds the perfect pop of flavor to a wide variety of meals and recipes. I’ve also included several ways to use homemade onion powder at the end of this post.

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RELATED: Learn how to plant and grow onions here, then follow these tips on when to harvest onions and cure them for storage. Or try our easy quick pickled red onions recipe!

What kind of onions should I use to make homemade onion powder?

You can use any kind of onions to make onion powder: red, yellow, white, sweet, spicy, small, large… We tend to grow mostly sweeter yellow or red onions, so our finished onion powder nice and sweet as well.

We often make homemade onion powder with immature onions that we have to harvest prematurely, or ones that have started to bolt (flower). Since those onions can’t be cured for long term dry storage, this is the perfect way to preserve them before they go bad! Even better, you can use all parts of the onion (including the green tops), so this is an excellent way to reduce waste overall.

Supplies Needed

• Onions – however many you wish or need to use. To make a full pint of powder, we used most of the onion bulbs shown above, plus about half the greens.
• A food dehydrator or oven – pros and cons of each option explored to follow.
• A good blender, food processor, or coffee grinder. We use a Vitamix.
• Airtight storage containers, such as mason jars.

Oven-Drying Versus Using a Dehydrator

You can make onion powder in a food dehydrator (our preferred method) or dry onions in the oven. I’ve included instructions for both below. Though it does take longer, we prefer using a food dehydrator for a number of reasons.

First, using a dehydrator allows us to set it and forget it. No stirring and fussing over the hot oven needed. There is also zero risk of burning the onions, ensures they get 100% dry as needed, and promotes even and consistent drying.

Another perk (in my opinion) is that a dehydrator allows us to dry the onions on a lower temperature, which better preserves the nutritional value. As explored more in our Fire Cider recipe, onions have stellar immune-boosting, inflammation-reducing properties. Yet when food is exposed to heat over 118°F, many of the beneficial nutritional properties, antioxidants, and active enzymes are reduced or destroyed. Therefore, we like to dehydrate onions around 100-110°F – low and slow!

Instructions to Make Onion Powder

1)  Peel and Slice the Onions

Wash the onions to remove any excess dirt, and trim off the tough root end. I also like to cut off the green tops and set aside to process separately from the bulbs. Peel and remove the outer papery skins of the onions.

Next, cut the onions into thin, even slices. The thinner the slices, the more quickly they will dry. Furthermore, the more consistent the cuts, the more evenly they’ll finish drying together. We typically aim for about 1/8” to 1/4″ thick (if I had to measure – which I don’t). For green onion stems, you can either cut them into rounds or long slender pieces.

Lay the slices of onion out evenly in a single layer on your food dehydrator trays as you go. You can pack a large amount on to each tray! The pieces can touch side to side, but make sure they aren’t piled on top of each other. We need some space for good air flow between them.  

PRO TIP: Did you know that holding a piece of citrus in your mouth while chopping onions helps reduce the sting and tears? It really works!

2) Drying Onions in a Dehydrator

Load up your food dehydrator with its trays full of onions, and turn that puppy on! We choose to dry ours on about 100-110°F. Again, this is because we don’t want to overheat and essentially “cook” the onions, denaturing its beneficial enzymes and antioxidants. If you aren’t overly concerned about that, you can use a warmer setting (around 135°F) to get it done much faster. It will taste just as good!

The time it takes to fully dry will vary. It depends on your dehydrator or oven, how you prepared and organized the onion, and the temperature you use. When we used our old Nesco dehydrator, it took several days on 110°F to completely dry. Our Excalibur dries it nicely in about half that time, and could easily do it in less than 12 hours on a higher setting than we use. (Keep reading below to see how to tell when they’re “done”.)

PRO TIP: Onions smell very pungent as they dry. If possible, you’ll want to put the dehydrator in a separate room with an open window. We usually put ours in the garage.

Drying Onions in the Oven

To dehydrate onions in the oven, prepare them in the same fashion as described above. Next, spread them in a thin layer on a baking pan covered with parchment paper or a slotted baking sheet.

Bake the onions at 140°F (or the lowest setting possible) until they are completely crunchy dry. Stir or toss and re-spread the onion bits every 30 minutes as you go. Drying onions in the oven will take several hours.

3) Check Doneness

Before removing the onions from your dehydrator or oven, check to make sure they are totally crispy dry! If you try to break them, the dry onion pieces should snap and crack crisply in half, and not bend or be malleable at all. If they’re still bendy or soft instead of crunchy, keep on drying! If too much moisture is left, your onion powder will clump up later in the storage container

You may find that some are done and some are not. Also, onion greens dry much faster than the bulb portion. In that case, you could either pull out the crispy ones and continue to dry the others, or just keep drying it all. We’ll often keep all the green onion leaves on separate trays than the onion slices. That way, we can pull out the trays of greens when they finish more quickly than the rest.

4) Grind into Powder

Once the onions are completely dry, it’s time to grind the crispy bits into homemade onion powder! This can be done in a blender, food processor, or coffee grinder. In a Vitamix, the result is a super fine, fluffy onion powder. Pulse and grind it until all the chunks appear to be broken up.

How to Store Homemade Onion Powder

Finally, transfer your finished homemade onion powder into an airtight storage container. We typically use mason jars, either half-pint or pint-sized, depending on how much we make. Repurposing old spice containers would work well too! You’ll probably want the assistance of a funnel here, so you don’t spill your precious goods. Our canning funnel is our best friend when we’re working with mason jars.

Ways to Use Onion Powder

Use homemade onion powder in a wide variety of dishes and recipes. Use it anywhere a subtle onion flavor would be welcome, such as soups, stews, sauces, fresh salsa, guacamole, sautéed or roasted veggies, pumpkin chili, hummus, homemade vegetable broth, salad dressing, veggie dips, egg dishes and more.

It’s also excellent sprinkled in with cooking rice, lentils, or pasta, or even worked into homemade sourdough or herb sourdough pizza crust. Mix some with salt to create your own DIY onion salt blend! Really, the options are endless.

I told you it was easy!

Congratulations, you have successfully made your own onion powder! I hope you enjoyed this article, and feel empowered and excited to go make your own. Please feel free to ask questions and leave a review below. If you liked this tutorial, you may also enjoy: How to Make Garlic Powder or How to Make Homemade Chili Powder. The process is very similar, but with a few minor tweaks.