I started off with 20 giant bulbs of garlic and peeled them all.
Then I sliced them all up. Not paper thin, just ..... sliced them and kept them as uniformly the same size as possible and laid them out on the trays.
I did not let the scraps go to waste! I put them in a pot of chicken bone broth I had going at the time.
Then I dehydrated the garlic at 95 degrees for approximately 10 hours. That time will vary depending on thickness. Also, you could crank up the temp a bit too, but I set it up and went to bed.
Once it was dried, I then just put it in my little food chopper and whizzed it up. I used a mesh strainer to sort out the pieces from the powder. I then put the pieces of garlic back in, added more garlic, and whizzed some more. Once I got tired of all that whizzing, I deemed some minced garlic and the rest garlic powder.
I then stored it in glass jars with lids. I considered adding a few grains of rice to absorb any moisture, sort of like you do with your salt shaker, but I decided I'd first wait and see if I had any clumping issues first. So far I've not. It's been over a week and it's still nice and powdery. But there's always that option too.
I went on to do the same with my onions! It's so awesome to make a recipe and just grab a handful of dried garlic and onions and toss them in instead of having to peel and slice! It makes whipping something up even easier!