Dry air pulls moisture from skin and muscle tissue. That's why exposed skin gets dry and cracked during the winter months. Jerky is just dehydrated lean meat, so it stands to reason that all you need to make jerky is lean meat and dry air, which is the traditional method of making jerky. Now, there are two methods of making jerky. Most popular method is cooked jerky, where the meat is cooked throughout. That's how all the bagged jerky out there is made. Second method is air drying, which is how MKader's father in law prepares his. The meat is not cooked, just dehydrated. Food dehydrators are little more than a heating element and a fan; they cook the meat more than they dehydrate it. You don't really need either. As MKader said, all you really need is to hang it up and let nature do its job. If it's not cold or dry outside, you will need to do it another way. Cooked jerky you can just throw it in an oven or smoker, easy peasy. If air drying, not cooking, you don't need a food dehydrator, just a box fan contraption as shown above.