Freeze-dried roses are rose blossoms or petals that have been subjected to quick freezing and pressurization, such that they are almost instantly dehydrated and preserved. They look and smell just like fresh roses in most cases, but are brittle and firm to the touch, rather than being soft. Roses prepared in this way are popular in dried wreaths and floral arrangements because of how closely they resemble fresh-cut flowers. It is also common to find freeze-dried rose petals at weddings and other special ceremonies. Preserved petals are often much less expensive than fresh petals, but they have the fragrance and the “real life” look that many silk imitations do not.
The actual freeze-drying process is not complicated, but it is challenging for many home gardeners because of the equipment involved. Most of the time, casual florists and gardeners looking to preserve roses will simply hang them out to dry. Roses dried in the air are preserved, but tend to lose much of their color and adopt a more muted fragrance in the process. They also tend to look shriveled, and take on a decidedly “dried” look. The same is not usually true with freeze-dried roses.
Usually, freeze-dried roses usually look exactly the same before drying as after. Most people will be able to tell the difference upon closer inspection, but at first, the resemblance between fresh and freeze-dried flowers is striking. The color, petal angle, and overall vibrancy remains constant.
Much of this owes to the quick dehydration process at work in freeze-drying. The process relies on a scientific principle known as sublimation. In sublimation, matter changes directly from a solid to a gas, without first becoming a liquid.
When a rose is placed in a freeze-drier, it is instantly frozen. Flowers, like most organic matter, are made up mostly of water. This means that all of the rose’s water molecules freeze, turning to ice. The pressure in the drying chamber then increases, causing those ice molecules to evaporate as water vapor.
Left behind is a rose petal seemingly frozen in time. The color, smell, and everything about the flower's appearance is the same, except that all water has been removed. Freeze-dried roses are a bit fragile, and can be brittle to the touch. They are preserved, however, and will not fade, droop, or discolor, at least not for quite some time.
Freeze-dried roses are very popular amongst florists who want to create fresh-looking bouquets that will last. It is often less expensive to freeze-dry a particularly pretty bouquet than it is to pay for an arrangement to be recreated in silk, or constantly refresh the arrangement with new blooms. Preserved rose wreaths and decorative arrangements are also easy for florists to sell ready-made, as they will look fresh for many months on display.
Event planners often seek out freeze-dried rose petals for events like weddings and photo shoots, as they are often much more economical than fresh petals. It takes a great many roses to create enough petals for most special events, and ordinary dried floral petals do not usually offer the same glossy look. Many freeze-dried rose distributors are able to resource petals from damaged or otherwise defective flowers, which lowers the overall cost. The storage and transportation of freeze-dried decorations is often much simpler, as well. No refrigeration or temperature controls are required at all.