Onion powder is very easy to make...Before I had a dehydrator, I would dry onions in the oven...All you need is your dehydrated onions and cornstarch. I believe I have about 1 cup of dehydrated onions in the picture below.

Put those in the blender with about 1 tsp of cornstarch...then grind...the cornstarch keeps the onions from sticking together and becoming gummy...if you look at a store bought spice, you will see LOTS of additives...if you make your own, you are getting a "next to pure" product.
After you grind it, you need to sift out any missed chunks..

blend this again....until you have all the onions ground into a powder...

place into a container and label...there you go...your own onion powder...(keep in mind that this will be a lot stronger, and you need less of the product when cooking or preparing mixes)
