Bring to boil, then turn down heat and lightly simmer as long as you want. You may need to add more water as the water simmers off. Your saucepan can sit on your stovetop for a few days, and only turn on the heat to reactivate the smell as often as you like. Discoloration of the orange slices is normal and they can be used for up to a few days. After the first batch has expired, replace with a new batch of ingredients and fresh water and continue enjoying the lovely aroma throughout the season!