Garlic begins to dry as soon as it is harvested; it continues to slowly lose moisture until it is eaten or stabilized with one of the methods discussed below. Until you take steps to stabilize your garlic it will continue to lose moisture and become hotter and more pungent.
Dehydrating garlic stops this process and preserves the garlic at whatever pungency and flavor level it was when it was sliced and dried. Since drying ruins the satisfying crunch of fresh garlic you may want to consider pickling or preserving as well. Garlic dried in a dehydrator (not a hot oven) will retain the beneficial health compounds that are destroyed by high heat. The idea is to dehydrate the garlic, not cook it. Crushed, chopped or powdered garlic that has been dried results in odorous fat-soluble polysulfides that circulate in the lymphatic system and have anti-tumor properties and other health benefits.