When canning season is over and I have stored enough onions to last through winter, I have just enough onions remaining to follow my favorite homemade onion powder recipe.
To make homemade onion powder, start with 2 pounds of organic onions from your garden or local farmers market. Peel the dried skins off the onions, and then cut each onion into approximately one-eighth-inch-thick, round slices. Separate the slices into individual rings and put them in your solar or electric dehydrator (an oven set to a low temperature will also work). You will know the onions are sufficiently dried when you can pick up a ring and break it like a potato chip.
After the onion rings are totally dry, place them in an airtight bag or container until you’re ready to use them. When you need some fresh onion powder, remove a few of the rings from the airtight container and grind them in your blender, food processor or coffee grinder until they’re powdery. A mortar and pestle will also work. If you wait to grind the powder until right before you use it, then it will be freshest.
You can use homemade onion powder in cooking the same way you use store-bought onion powder, only the taste is fresher and more pungent. Use onion powder in soups or stews, on popcorn in place of salt, or mixed into dips and salad dressings.