Hang Dry vs Rack Drying Cannabis – Which method should you use?

When it comes to the drying step of the cultivation process, you may have heard a lot of varying opinions and preferences as to the best method of drying. There is one faction that is accustomed to the traditional hang line & box fan, “do-it-yourself’ way of things. Even some of the largest recreational operations in the world hang dry their product. Why is that? Is there actual evidence as to why one would prefer to use hang drying on a commercial scale vs using a rack & tray system?

Why Hang Dry?

One of the main reasons that some cultivators choose to continue to hand dry is the low initial cost of the method – hang drying with hangers or wire can carry a much cheaper price tag than buying stainless steel racks and medical-grade plastic or stainless steel perforated drying trays. Hang drying also allows the growers to turn over their grow rooms quicker and save on setup for the drying cycle – as they don’t need to spend time wet trimming their flower to place the crop on racks and can instead just hang the entire branch with flower and all. Proponents of hang drying will also say that the natural shape of the flower is left intact this way and prevents what is known as ‘pancaking’ in the tray drying world. You may also hear hang dry advocates say that drying with the full stem results in better retention of cannabinoids and terpenes when compared to tray drying – although any empirical evidence remains hard to come by.

On the flip side, some industry veterans claim that hang drying is not the way to go as it is much less spatially efficient, that there is a greater smell nuisance as a result, and that there is an increased risk of mold and mildew contamination due to the increased overall time in which it takes to hang dry vs tray drying.

Why Rack Dry?

Rack drying has become more and more popular over the last decade or so as large commercial cannabis operations have popped up due primarily to cannabis legalization across the U.S. and other countries. Rack drying systems tend to have a lesser risk of contamination from mold and mildew building up – this is due primarily to the increased rate of drying that you get from a more evenly distributed airflow and dry when using medical-grade (& GMP approved) perforated trays. From a security standpoint, there is much less of a smell concern as well – as tray drying helps to reduce and contain smell emissions. From an operational workflow standpoint as well, tray drying allows for a more space-efficient and organized/professional feel to your post-harvest operations. This is something that is critical when being evaluated to a GMP standard – which is becoming of greater concern as entire nations begin to regulate the cultivation and sale of cannabis and federal regulators begin to turn a more watchful eye on the industry in general.

Even with all of these efficiencies proposed by tray drying, some of the industry purists argue that with the increased speed of drying using trays that the quality of the end product is adversely affected. This may be true if things like temperature and airflow variables are not refined and adjusted accordingly. Tray drying in fact requires a greater need for constant monitoring and controls. 

At Cann Systems we offer both options to our customers for their CDS drying machines. All in all, it comes down to the preference of those responsible for the cultivation of the crop. Overall, the hang dry method may take less intervention and supervision than tray drying. That said, it is really whether your post-harvest team prefers dry trimming to wet trimming that should really determine whether your SOP involves hang drying or tray drying. Whether you choose to hang or tray dry – either, combined with the highly dialed environment provided by Cann’s line of CDS machines – will help you eliminate adverse risks in your post-harvest drying process and keep your crop looking and tasting its finest!