Preheat the oven to 80–90°C (fan). Line baking trays with baking paper.

Slice the citrus into thin, even rounds about 3 mm thick. Pat both sides dry with paper towel.

Arrange the slices in a single layer with no overlapping.

Dry in the oven for 2–3 hours, flipping halfway.

Limes dry fastest: 1.5–2 hours.

Oranges and blood oranges: closer to 3 hours.

Check for doneness: slices should be dry, glassy and feel firm rather than tacky.

Optional: turn off the oven and leave trays inside for 20–30 minutes with the door ajar.

Cool completely — they crisp further as they cool.

Store in airtight jars for up to 6 months.