Freeze drying: the technique that dries and cures cannabis in 24 hours

Growing cannabis is a process that requires dedication and, above all, patience. This is well known to experienced cannabicultors since, once they harvest, they must wait for the buds to go through the drying and curing process. In some cases, this may last up to a month and a half or two more, but… What if we tell you that there is a technique that dries and cures marijuana flowers in just 24 hours?

So-called freeze drying (also known as lyophilisation) is a technique commonly used to preserve perishable foods through dehydration. The process involves dehydrating the material using freezing and then, by reducing the surrounding pressure, allowing the excess frozen water to evaporate. In this way we eliminate practically all the moisture contained in the product and thus preserve it for longer.

Some pioneers of the cannabis sector have found in this technique (applied for years in the food sector) a possible way to make a more efficient cannabis processing. With famous figures as representative as Ed Rosenthal supporting the freeze drying, many have begun to see the possibilities that this technique offers.

In a regulated market such as the United States, it is inevitable that technological advances will be made to improve production and optimise the quality of the final product.

Freeze drying and cannabis: does it really work?

For years, some growers have investigated the possibilities of lyophilisation to dry and cure marijuana flowers without obtaining good results. Because of the legal framework and the “special” circumstances of the cannabis industry, it is not always easy to apply advanced techniques and the necessary resources are not always available.

The first attempts at  ‘freeze drying’ were a fiasco because the machines used for it were not designed to dry cannabis buds, but were intended to dehydrate apples or other foods. The conditions offered by these devices were too aggressive for the delicate trichomes, which ended up falling off. In addition, the resulting cannabis was too dry and crushed; and a lot of terpenes and cannabinoids were lost, so the final product had less aroma and flavour than the dried buds with the traditional method.

However, some understood that it was a matter of adjusting those parameters that failed to achieve lyophilisation of cannabis flowers while keeping intact their trichomes and terpenes profiles. And they finally made it.

How does freeze drying work?

The process of ‘freeze drying’ to dry and cure cannabis buds consists of several phases:

• First, the fresh (freshly harvested) buds are placed in a cold chamber. It is important that the flowers are arranged on steel shelves without being crushed and with great care.
• Once in the chamber, the below freezing temperatures freeze the buds transforming the water they contain into small ice crystals.
• Once these crystals have formed (with the moisture contained in the flowers), the pressure inside the lyophiliser is reduced to create vacuum.
• The combination of low pressure and low temperature activates a process called “sublimation”, which converts crystallised water into gas without passing through the liquid state, but preserving the molecular structure of the lyophilised substance without causing damage to this structure.
• Finally, this moisture in the form of gas is carried by the vacuum into a cooler condensation chamber. The end result is a cannabis flower to which the remaining moisture has been extracted, but that maintains all its flavour, colour and aroma.

Differences between ‍freeze drying’ and the traditional method

You may be wondering what differentiates dried and cured flowers by lyophilisation from those that have been processed with the traditional method. Actually, the difference is huge, as the buds that have gone through the freeze drying look incredibly similar to the fresh flowers you see when they are still on the plant.

Unlike what we are used to, lyophilised buds do not reduce their size (as those that have been dried hanging the plant down for 15 days do), and their colour, aroma and flavour are also the same. With live green buds and an intact terpene profile that many have begun to nickname “live resin flowers”.

What benefits does freeze drying offer?

Actually, the benefits of using this technique are numerous, although it is true that it requires an initial investment that not all cannabis producers can afford.

In the United States, where this method is starting to be implemented, medium- and large-scale farmers are always looking to optimise their resources and obtain a higher quality in their product. In a competitive market such as the American one, this revolutionary drying technique can represent a great differentiation for a brand; however, as we mentioned above, not everyone can afford the necessary equipment to carry it out.

Let’s see what benefits ‘freeze drying’ has to offer:

• Undoubtedly, one of the advantages is that cannabis flowers will be ready to use in just 24 hours compared to the 15 days of drying plus the approximately 30 days of curing.
• It is a method that eliminates fungal problems that can occur during traditional drying.
• Some consumers claim that the flowers dried under this new technique produce a more energetic effect that they describe as blissful. In addition, users claim that smoking this type of cannabis results in a smoother experience for the throat and less irritating for the airways.
• Without a doubt, the visual effect is one of the great claims of the freeze drying, as the buds barely shrink in size and are twice as large as the normally dried buds. Its colour is bright green and exudes an incredible aroma.
• There is no excess moisture, drying is perfect.
• Trichomes are best preserved. Laboratory results have confirmed that, by this technique, there is less resin loss; this results in a large number of cannabinoids and terpenes. And with this technique you avoid trichomes breakage or detachment, the buds are literally “frozen” in time, right at that point (freshly harvested) in which they express their greatest potential and beauty.
• Moisture levels can be minimised to 1%, so the cannabis dried with this mode is ideal for extractions, since water is the enemy number one of the process to make some cannabis extracts.

Conclusions

Many argue that freeze drying will revolutionise the way flowers are presented to the final consumer. This is a way to remove excess moisture while keeping the bud intact in record time. Although some prefer to stick to the traditional way because they consider it to be more artisanal, the public who will choose the product that is higher quality will have the final say. Or maybe even this method has come to expand the cannabis formats offer available on the market, as extracts and concentrates did back in the day.