In the Dehydrator

1. For a dehydrator, prepping your onions is the most important part. Use a mandolin to cut evenly thin slices (1/8” to 1/4″ thick) throughout your onions.
2. Spread on your dehydrator trays in one single layer each.
3. Cook on as low as 100-110°F, which will take a couple days to dry but will preserve the most nutrients. You could increase to 135°F and they will be ready in about a day. The warmer you go, the faster they will dehydrate.
4. Time will very every time you make them, it will depend on the moisture in the onion and how thick or thin the onions are. Cutting onions thicker will allow you to make more, but will double drying time. So in terms of time, the tell-tale sign they are done is when they crumble in your hands, and cannot bend at all, they are ready. There should be absolutely no moisture left.
5. Crush into a fine powder with a dry blender, food processor, or coffee grinder and store in an air-tight container with some rice to absorb moisture.

In the Oven

1. If you prefer to use the oven method, you could totally slice the onions like we did above and bake them, however you’ll get a lot more onion powder, less likeliness to burn, and a more even cooking consistency by grating them instead.
2. Preheat your oven to 170°F (75°C) and line two baking sheets with parchment paper to prevent sticking.
3. Cover a bowl with a couple layers of cheesecloth. Peel your onions and grate them into the bowl using a cheese grater or microplane. You could also use a food processor.
4. Wrap the onions in the cheesecloth, twisting at the top, and squeeze out as much liquid as you can. (The onion juice can be used in marinades and salad dressings!)
5. Spread out the onions on the baking sheets in an even uniform later and bake for about 5 hours, or more importantly, until they are completely dry and crumbling. The type of onion you use will determine how long they will need to cook. Checking every 30 minutes after 4 hours is a good tip.
6. Remove totally dried onions, allow to cool completely, then add to a blender, food process, or coffee grinder, and store in an air-tight container with some rice to absorb moisture.