Bake your cookie sheets for about 30-60 minutes in the oven at 350-400 degrees. You will be amazed how good the cookies smell! And if you like, you can try one either. The baking time really depends a lot on your oven. If you feel they are still pretty soft and wet inside, but already browning a lot outside at the bottom, you can use two baking sheets instead of just one. If they become brown too quickly on the upper surface you can cover them with a sheet of aluminum foil or place another empty baking sheet above the cookies in your oven.
Once the cookies reach the desired state of golden brown and not too soft inside, either move them into your dehydrator for 3-4 hours to remove the remaining moisture or leave them in your oven at only 100-140 degrees until you feel they are “dry”. Make sure they do not burn.
To add some ventilation you can put a wooden spoon between the oven door (don’t use metal spoons, they get hot, and no plastic for obvious reasons!). I myself do not add ventilation. Instead I use the rest of the heat in the cooling oven after it is turned off to dry off my cookies a little longer before they go into the dryer.
Your resulting homemade dog treats are very light and porous and really brittle and dry, even inside. I bet your furry buddy will love them!
If you have a picky eater, try replacing the water with homemade unsalted chicken or beef broth to spice things up.
The cookies hold together fairly well and should not crumble a lot. If they do crumble, they are still too soft and not really dried. Store them in sealable plastic bags or an airtight container at room temperature in a dry place.
By the way …
Dry cookies usually stay consumable for quite a while even without added preservatives, if stored correctly. I usually put some uncooked rice into my container with the cookies to take moisture away (just as people do it in salt dispensers). If you want yo be on the safe side, here’s some additional advice: Cookie dough as well as the freshly baked cookies can be stored for some weeks in your freezer like mentioned above. Thaw the dough to process it into cookies for baking. Or bake the cookies first, let them cool and freeze them in airtight sealed bags. Thaw the ready baked cookies when needed and just use them. You can do the same with your homemade “human” cookie leftovers from Christmas and find out that they will be just as yummy on easter Sunday. 🙂