If you love the taste of fresh raspberries, preserve their deliciousness by dehydrating the berries in your conventional oven. Dehydrate raspberries to store them for a long time. The raspberries will last 6 to 12 months in an air-tight container. Rehydrate the raspberries by soaking them in water. Add the raspberries to oatmeal, cereal, trail mix or your favorite snack. The raspberries require a long time to dehydrate, but the result is rewarding.
Use only ripe, fresh raspberries.
Check the berries for damage or alterations. Discard raspberries that have imperfections.
Clean the raspberries under cold water. Remove dirt, debris and stems from the berries.
Dry the raspberries on paper towels.
Boil enough water in a cooking pot to cover the berries, but don't include the berries in the pot while the water heats.
Place the raspberries in the boiling water for 30 seconds. This cracks the skin of the fresh berries so that moisture is removed while they dehydrate.
Remove the raspberries from the boiling water and immediately place them in a bowl or pot of cold water to prevent them from cooking.
Spread the raspberries on a cookie sheet. If you have many raspberries, use more than one cookie sheet to allow for adequate drying room.
Place the cookie sheet with raspberries in a conventional oven. Set the oven at 100 degrees Fahrenheit. Raspberries take 10 hours to dehydrate.
Remove the raspberries from the oven. The raspberries are finished dehydrating once they are brittle and no longer moist inside. Squeeze the berries to ensure that they do not contain moisture. Place the raspberries back in the oven if they are still moist and not brittle.
Let the raspberries cool.
Store the raspberries in an air-tight, moisture-free container in a cool, dark environment, such as a refrigerator or basement.