Freeze-dried rose petals can be a semi-permanent reminder of a precious memory or a decorative element for an important event to come. But whatever use you have in mind for your freeze-dried rose petals, you should know that drying them is not a quick procedure. To make freeze-dried rose petals, you will need a vacuum freeze dryer with an adjustable temperature setting. The freeze dryer is easy to use but quite expensive. If freeze drying rose petals is something you only plan to attempt once, consider having them professionally freeze dried.
Use pruning shears to harvest your roses. Wear gloves to protect your hands from thorns. Cut growing roses when the buds have opened fully and the petals can be easily removed.
Cut the stems of your roses on a diagonal and put them in a vase for at least 12 hours.
Carefully remove the petals from your roses.
Discard any petals that are damaged, spotted or torn.
Set the freeze dryer's temperature to -5 degrees Fahrenheit. Close the dryer's door and turn on the vacuum for 10 seconds to seal the door shut.
Once the freeze dryer has reached -5 degrees, release the door and lay the rose petals directly on the freeze dryer's tray.
Close the freeze dryer's door and turn the vacuum on. Allow the rose petals to freeze dry at -5 degrees Fahrenheit for 48 hours.
After two days, increase the freeze dryer's temperature to 0 degrees Fahrenheit. Allow the petals to dry at that temperature for another 48 hours.
Increase the freeze dryer's temperature by 5 degrees Fahrenheit every two days until the temperature reaches 20 degrees.
Once the rose petals have dried at 20 degrees Fahrenheit for two days, open the freeze dryer and touch the rose petals. Dried petals will not be cold because they do not contain moisture. If the petals are cold to the touch, put them back into the freeze dryer for another 48 hours. Check them again and repeat this process if they still are not dry.