Drying citrus fruits is a great way to preserve and intensify their natural flavour. Select fruits that are newly ripe and without blemishes so that the peel and flesh are edible once they are dried. Because citrus fruits are acidic and have a high moisture content, drying them is a slow process of eliminating the moisture without burning the essential citrus oils. Dried slices of citrus fruits can be used as a seasoning or to add a bright citrus scent to a potpourri mix.
Clean the outside of the citrus fruit thoroughly under cold running water using a nonabrasive scrubber.
Place the fruit on a clean cutting board and cut them into uniform slices that are 3 to 6 mm (1/8 to 1/4 inch) thick. Naturally, thinner slices of citrus will dry faster.
Arrange the slices of citrus on a stack of two paper towels and cover them with two more towels. Continue stacking single layers of slices and double layers of towels until all slices are used.
Set the oven to 65.6 degrees Celsius (150 degrees Fahrenheit) and carefully flip the stack of citrus slices and paper towels.
Peel away the paper towels and transfer the citrus slices onto wire mesh pans or cooling racks. Leave 1.2 cm (1/2 inch) of empty space between slices and around the edges of the pan or rack. Sandwich the citrus slices by covering them with a second wire mesh pan or rack to keep them from curling.
Slide the filled wire mesh pans or racks into the centre of the warm oven and allow them to dry for approximately six hours with the oven door open about 15 cm (6 inches). Turn on a ceiling fan or place a portable fan near the open oven for better air circulation.
Test to make sure the citrus slices are completely dried by bending them in half. They will still be pliable when dry but will not release any juice when bent or squeezed.
Store the dried citrus slices in an airtight glass or plastic container on a cool dark pantry shelf.
Crushed dried citrus can be added to a variety of sweet and savoury dishes. Try mixing dried slices of lemon, lime and orange to create a citrus blend that works well in the kitchen or potpourri bowl.