Truffles can be stored at room temperature for up to 4 days because of the fat and sugar content. But the finished truffle should be stored in an airtight container. They do contain cream, so if you want to store them longer than that I recommend keeping them in the refrigerator for a few weeks or freezer for up to 3 months. Chocolate is going to taste best at room temperature and as fresh as possible. A long time in the fridge could result in a stale flavor and or other flavors absorbed from the fridge.