Place blueberries in a pot of boiling water and boil for about 30 seconds. Transfer to ice water (or really cold water).

You have the option to leave them whole or slice them in half, depending on your preference. Sliced blueberries will dehydrate faster and more evenly, while whole blueberries may retain more of their natural shape and size.

Spread the blueberries out in a single layer on a dehydrator tray or a lined cookie sheet. Make sure the berries are evenly spaced and not touching each other, as this will promote even airflow and prevent them from sticking together during the drying process.

Set your dehydrator to a low temperature, typically around 135°F (57°C), and let the blueberries dry for an extended period of time. The dehydration time can vary depending on the moisture content and the size of the blueberries, but it usually takes between 8 to 18 hours. Keep an eye on them and rotate the trays occasionally to ensure even drying.

The blueberries are ready when they are shriveled and have a leathery texture. They should not feel damp or sticky when touched. If you notice any signs of moisture, continue drying them until they reach the desired consistency.