This post was most recently updated on March 18th, 2020
Last year I scored a MASSIVE bag of onions for super cheap. We ate what we could, but there is only so much french onion soup you can expect small children to eat.
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So I did the next best thing. I made my own onion powder!
And do you know what, it is so so so easy to make your own onion powder at home! That was almost a year ago and we are still using the onion powder several times a week in different dishes.
You can use onions that are starting to go soft, and even ones that are just starting to sprout to make your own onion powder at home.
Reasons to Use Onion Powder
You may wonder what is so good about onion powder, why not just use fresh onions?
1. Onion powder lasts longer
Onion powder is shelf stable for several years, and while fresh onions do store well in a cool dark place, usually by about 6-9 months even then they will start to sprout.
2. Onion powder is quick
For people in a rush, grabbing some Onion powder off the shelf is much faster than peeling and chopping a whole one.
3. Perfect to make seasoning with
If you are making marinades, your own spice mixes or wanting to make your own onion dip, then onion powder is exactly what you need.
How to make Onion Powder at Home
1. Select your Onions
You can use onions that are starting to soften or slightly sprout, but the most pungent onion powder is made with fresh onions.
Remove any onions that are rotten or moldy.
2. Peel and chop
Peel your onions and slice them 1/4inch/5mm thick. This is long and tedious, but you only have to do it once. Put your favorite show on the telly and sit down to do it.
Open your windows and wear some swimming goggles to protect your eyes.
The thinner you slice them, the faster they will dry. It is most important that the slices are even however, as the thicker ones will dry more slowly.
You can dry your onions in a dehydrator following its directions. I usually do it at 40C for 8-10 hours. You want the onions to be hard and crispy, not rubbery.
You can dehydrate your onions in the oven, set it to its lowest setting usually 150-200F/70-100C and place the onion slices in a single layer on parchment lined trays.
Cook for 8-10 hours or until done. If you have a fan option on your oven, use that too, it will dry it out faster.
The most efficient way of doing this is in a Nutribullet, but a standard food processor, coffee or spice grinder, or even a mortar and pestle will work too.
Pass your newly made onion powder through a sieve before storing it. The larger pieces you can either re-crush or add to soups or stews.
Storing Homemade Onion Powder
Store your homemade onion powder in a sealed jar. If you have spare silicone sachets that soak up moisture, pop one in there too. Adding a tablespoon of uncooked rice in a small mesh bag has the same effect.
Onion powder made this way should store for several years before the potency will start to decline.
Troubleshooting Making Onion Powder at Home
Help my onions made a thick paste not a powder!
Make sure your onions are totally dry before crushing/blitzing. All is not lost. Spread your paste out on some parchment in the oven or dehydrator and dry it some more. Another 2-4 hours should be enough.
Then return the powder the the nutribullet and try again.
Also, make sure the dried onions are totally cool before you try and blend it. The heat of the warm onions can cause condensation to happen in the food processor making the powder clump.
My onions are still rubbery!
Keep drying them, you need them to snap or crumble when you bend it. Onionsc can take up to 14 hours to be properly dry.
I don’t want my whole house to stink!
Well, it is only onions, and only for a short time. But, yes, your house will smell like onions for a few days. If you are using a dehydrator, move it to a room with a window, and leave the window open a little while you are drying the onions.
Help, my onions look cooked!
Ideally you will be using a dehydrator that cannot get hot enough to cook the onions.
If you are using the oven, and it cannot reduce it’s temperature any further, you might need to look for a different way of dehydrating your onions.
You can still use your onions that looks cooked as long as it is crispy and dry. If it is burnt you will want to throw it to the chickens as it will taste very bitter.
Tips for Making Onion Powder at Home
Buy onions in season, this is usually late summer or early autumn/fall. When there is a lot around it is cheaper to buy them.
Look for big bulk deals – I got a 15kg sack for very cheap.