How to Make Onion Powder From Scratch

Save money on a staple for your spice rack

High Angle View Of Minced Onion With Garlic Salt And Powder In Bowls On Wooden Table
••• Michelle Arnold / EyeEm/Getty Images 

Are you tired of forking over big bucks for a little jar of onion powder? Then you'll definitely want to learn how to make it at home. It's extremely simple and you can save a lot of money while keeping this staple in your spice rack.


There is no great secret to onion powder and all you need is a few fresh onions. It's the perfect way to use up onions that are just starting to get past their prime as well.

In an hour or so, you can have enough onion powder to last for quite a long time and it can also be used to make onion salt

One or two onions are often enough for the average family's use for a few months or more. You can always add more onions and make a larger batch if you like. If you find you have too much, give jars away to family and friends.


Begin by peeling your onions and chopping them finely. Spread the onion pieces out on a tray and heat in a 150 F oven or in a food dehydrator until dry. The onions are done when you can easily crumble the chopped pieces in your hand.

Allow the dried onions to cool before grinding into powder. Grind them up with a coffee grinder, spice mill, food processor, or mortar and pestle until it reaches your desired consistency. 

Storage and Shelf Life

Store your finished onion powder in an air-tight container in a cool, dry spot. You can also freeze any excess.

As with any dried spice or herb, it's best to shake the container at least once a day for the first week. This will distribute any leftover moisture evenly and prevent mold from growing.

Be sure to label the jar so you don't mistake it for other spices like garlic powder. An inexpensive option is a piece of masking or painter's tape on a recycled spice jar.

These tapes won't leave a sticky residue and are easy to remove, but they will adhere well until you wash the jar again.

Onion powder has a surprisingly long shelf life. A commercially dried powder can last as long as three or four years. However, your homemade version may not meet such exacting standards. Depending on how well it's dried, expect your onion powder to stay flavorful for up to a year in a well-sealed container. Since this is so easy and cheap to make, you might even consider making a batch as often as twice a year.

About Coffee Grinders

Coffee grinders make quick work when it's time to grind any spice. You'll get the finest onion powder from one and can always grind less if you prefer it a little more coarse.

It is best to designate separate grinders for your spices and your coffee. Things like onions and garlic are very pungent and the smell can be very difficult to remove from the grinder. Unless you enjoy onion-flavored coffee, this is not the ideal situation.

The good news is that coffee grinders tend to be pretty inexpensive. You can pick up a simple one just for your spices and keep your good one with all the bells and whistles for coffee.