Cannabis Drying Trays: What’s the Best For Buds?

Updated July 11, 2022

After months of meticulously caring for your cannabis plants, it’s time to harvest those valuable buds. And as satisfying as it is to trim the branches of a healthy cannabis plant covered in crystals, you’ve only crossed one milestone in the flower’s journey.

Now it’s time to ensure your hard work is properly preserved. This allows cannabis manufacturers and dispensaries to receive their buds at full weight, potency, and uncontaminated.

Fortunately, humans have become masters in the art of food and herb preservation. We’ve learned how to preserve fruit for future consumption and transportation. And we’ve figured out how to dry herbs such as cannabis so we can enjoy their aromas and medicinal benefits long after you’ve harvested those buds.

Why Does Food and Herbs Spoil?

We don’t usually give much thought to why produce, herbs, and meats spoil. However rest assured, cannabis cultivators think about it all the time. And the answer is simply this: the Earth recycles everything. The nutrients and elements you use to fertilize your cannabis plants are absorbed and assimilated as your plants grow and eventually flower.

When your plants die, nutrients such as Nitrogen, Phosphorous, Potassium, and Carbon are all reclaimed by the Earth through a process called “decomposition.” Decomposition (or decay) occurs when microorganisms work together using oxygen and water to break down organic material into simpler forms. These microorganisms include:

  • Mold
  • Bacteria
  • Fungus
  • Yeast

Eventually, excess nutrients not used by the microorganisms for reproduction are reintroduced into the soil. And this is a good thing. Decay creates a never-ending cycle of natural composting in the environment, making valuable nutrients available for the next life cycle of vegetation and wildlife.

cannabis drying trays prevent bud rot
Decay or decomposition is nature’s way of composting all organic matter. Microorganisms break-down foods using the water and nutrients found inside them.

The decay of cannabis works exactly the same. And preventing nature’s attempt to compost your crop too quickly is especially critical to cannabis farmers, who use nearly every part of the plant to generate revenue. The good news is, you can mitigate mold and prevent “bud rot” (the decay of your buds) using cannabis drying trays.

Why Do Cultivators Dry Cannabis?

Mastering cannabis dehydration will make or break your cultivation business. Properly drying cannabis increases your strain’s cannabinoid potency, which translates to higher sale prices. Efficient drying also sets your buds up for highly successful curing, greatly extending your flower’s shelf life and improving its aromas. In addition, drying your weed will:

  • Halt the growth of mold and prevent “bud rot”
  • Preserve cannabinoids and terpenes
  • Increase potency and aroma

The potential for dehydrating cannabis is uncontested. However, failure to dry your cannabis properly can have the opposite effect, leading to contaminated flower or terpene burn-off.

Properly Drying Cannabis to Prevent Mold

Finding any trace of mold in your cannabis crop is discouraging at best. And after being very careful to prevent mold during your plant’s vegetative and flowering cycles, the last thing you want is to find that mold has latched onto your flower during the drying process.

Fungus in the form of mold and yeast can single-handedly contaminate and ruin your entire harvest if left unchecked. It’s no wonder cultivators go to great lengths to reduce their bud’s exposure to any microorganisms while managing the climate in their drying room.

cannabis with mold and bud rot
Once mold sets in at the stem, it will quickly consume the bud, resulting in bud rot. When mold is visible on the flower, the entire plant is at risk and should be closely inspected for further signs of contamination. You should consider isolating infected plants.

Although mold can survive with little to no water, mold requires moisture to reproduce. The trick is to reduce your bud’s exposure to contaminants such as mold while you use cannabis drying trays to reduce the water content within the plant material. However, if you dry your flower too quickly, terpenes and lower cannabinoids will evaporate.

However, drying your cannabis buds too slowly will give mold the time and conditions it needs to reproduce and thrive. This has resulted in many cannabis cultivators using faster drying methods, even if it means burning off some of the terpenes. The loss of a little aroma is preferable to the total loss of valuable product.

Cannabinoid and Terpene Preservation

The terpenes that give your cannabis strain its unique aroma have lower boiling points than most cannabinoids. This makes it much easier to inadvertently lose terpenes to evaporation during the drying process. Drying your buds at a slow, steady rate helps prevent “terpene burn off.”

As you dry your flower, the trichome walls become more sturdy and less permeable. As the trichomes dry, the buds become less sticky and easier to handle. This also protects the bud’s resin and preserves the cannabinoids, terpenes, and flavonoids inside.

Preserving your plant’s terpenes also allows patients to experience the full-spectrum benefits unavailable in isolates or synthetic THC compounds. When terpenes and cannabinoids interact together within the endocannabinoid system, patients experience “The Entourage Effect.” So carefully drying your cannabis helps ensure adult users and patients glean all the positive effects your flower has to offer.

Increasing Potency and Aroma

Just as dehydrating fruit concentrates its sugars, drying buds and flower concentrates the cannabinoids and terpenes stored within the trichomes. When drying your flower, two processes take place to increase your bud’s potency.

Freshly Trimmed Cannabis Isn’t Dead Yet

Drying wet trim on cannabis drying trays allows the chemical reactions taking place within the cannabis glands to continue because fresh trim remains alive during the early stages of drying. This does not occur if you use a commercial dehydrator or oven immediately after trimming.

Allowing the enzymes within the trichomes (such as THCA synthase) to continue converting CBGA into THCA for as long as possible, helps increase cannabinoid concentration. And every little bit helps improve the profitability of your final product.

Cannabinoid Concentration By Weight

Removing excess moisture greatly reduces the water weight of each bud, which increases cannabinoid concentration by weight. There are farmers that believe when small pieces of the stem “snap” as you bend them, the plant material is dry enough to cure. However, commercial and large-scale cannabis cultivators should use moisture analyzers that use the precise weight of your flower to determine its relative humidity.

Whether you are using a commercial moisture analyzer, or the “stem-snap” method, your buds are ready to cure when their water content is around 14%. When your buds are curing, they will continue to dry down to about 10 – 12%. Keep in mind, using a moisture analyzer will prove more reliable and allow you to maintain a scientifically repeatable drying processes.

It’s important to note that a little moisture enhances your customer’s experience. If your flower drops below 10% moisture content, it will likely result in a harsher smoking or vaping experience as is often associated with old weed.

The small amount of water locked inside the trichomes is needed to stabilize and preserve the cannabinoids and terpenes. And don’t forget that your revenue is calculated by how much product you sell by weight. Over-drying doesn’t just burn off cannabinoids and terpenes, it cuts directly into your sales.

Methods of Drying Cannabis

There are several schools of thought when drying cannabis. Some cultivators prefer to trim their marijuana branches and then hang dry them. Others trim their flower immediately and then allow their buds to dry on a tray and drying rack. And some farmers use a bit of both methods.

Regardless of your drying preference, your drying room should maintain a dark, cool environment. Precise temperature and humidity will vary based on the geographical location of your dry room. However, it will generally fall between 55 – 65% humidity at around 65 – 70 degrees F. Different environment configurations will affect drying times and terpene preservation.

Now let’s take look at the differences between hang drying vs. using cannabis drying trays.

Hang Drying Cannabis Trim

Hang drying cannabis is one of the earliest methods of drying trim and flower. There are a couple reasons cannabis cultivators and farmers hang dry their cannabis plants after harvest. First, hang drying cannabis branches helps slow the drying process, preserving terpenes. This works well in environments with very low humidity. However, it can also facilitate the growth of mold and fungus in higher humidity environments.

Hang Drying Cannabis Plants
Some cannabis cultivators hang dry their harvested plants. This helps to slow the drying process, reducing terpene burn off in dryer climates. However, hang drying comes with a greater risk of mold in more humid environments.

Second, remember when we mentioned that freshly trimmed cannabis continues THC and CBD synthesis? Hang drying for a couple days can give you a final boost in potency by allowing the cannabis plant to generate a little more THCA before the plant enzymes cease to convert CBGA into THCA. This biological process also continues when using drying trays but to a lesser extent.

That said, hang drying cannabis also comes with a greater risk of mold and fungus contamination. As a result, most commercial cannabis cultivation businesses have adopted cannabis drying trays into part or all of their drying procedures.

Cannabis Drying Trays

As a commercial cannabis farmer, it’s important to maximize every square foot in your drying room. Poor use of space can create weak links in your production chain. At a glance, cannabis drying trays allow you to dry a higher volume of trim and buds in your drying rooms. And it’s best to choose drying trays such as Metro’s WavDri, which are designed to improve drying times while also helping to mitigate mold and contamination.

As with any manufacturing business, you must keep product moving.

  1. Mature, flowering plants await harvest
  2. Drying flower awaits curing
  3. Cured buds await transportation to a processor or dispensary

Cultivators frequently get “stuck” in the drying phase of cultivation, which slows inventory throughput. Cannabis drying trays dry buds faster so they can move on to curing, freeing up valuable space in your dry rooms.

Additionally, properly using cannabis drying trays helps ensure more consistent, predictable results so farmers can improve their daily operating procedures. Some drying trays, such as stainless steel or Metro’s WavDri, also excel in the prevention of pesky microorganisms such as fungus and mold.

Types of Drying Trays

There are many different types of drying trays, each with its advantages. The most common are aluminum, fiberglass, stainless steel, and polypropylene.


Aluminum drying trays are inexpensive and can be easily sourced. However perforated aluminum can occasionally “flake” or “shed” into your flower or buds, so it’s important to inspect each tray after drying rotations.

Stainless Steel

Steel drying trays can be found at a higher price point than aluminum trays and are great at resisting the growth of fungus. Stainless steel is highly durable and dishwasher safe. Cannabis drying trays manufactured using stainless steel will provide years of use before needing replaced.

Stainless Steel Drying Tray
Stainless Steel cannabis drying trays are easy to sanitize, preventing cross-contamination between strains. They are also proven to be highly durable and reliable for foodservice and cannabis processing alike.

Many cannabis cultivators would consider stainless steel trays “overkill,” as there are less expensive and more effective solutions available. However, their durability and convenient availability make them popular in many greenhouses and dry rooms.

Fiberglass / Composite

Trays manufactured from fiberglass have a higher price tag than that of aluminum, however, they are remarkably sturdy and easy to clean. Their non-porous surface makes them resistant to fungal and chemical contamination. And fiberglass will never rust or corrode.

fiberglass cannabis drying tray
Fiberglass drying trays are highly durable and lightweight. Although advancements have been made in drying tray technology, fiberglass trays remain a solid option when drying trimmed cannabis.

Because the surface is perfectly flat, moisture can collect between the buds and the tray. So to prevent mold from forming, it is necessary to rotate your buds more frequently when using trays with smooth surfaces.

Polypropylene, Plastic

Polypropylene drying trays are becoming the go-to for commercial cannabis cultivators. They are very durable like fiberglass and stainless steel and are usually more affordable. They can be sterilized in a commercial dishwasher to make sure each new batch of trimmed buds start with a clean slate, free from mold and other contaminants.

Plastic drying trays are lightweight, making them easier to handle and use. Medical grade polypropylene drying trays, like Metro’s WavDri, also incorporate antimicrobial additives to mitigate mold and fungal growth. The WavDri was specifically engineered to solve the problems cannabis farmers face when drying buds – mold, air circulation, dry time, and maximizing space.

Introducing WavDri Cannabis Drying Trays

Metro has been providing high-quality, innovative solutions to the foodservice industry for years. Now, they have stepped up to solve one of the most pressing challenges in cannabis cultivation – the safe, timely drying of buds and flower prior to curing.

Metro's WavDri Cannabis Drying Tray
The WavDri cannabis drying tray is specifically engineered to safely and quickly dry buds prior to curing.

WavDri trays are manufactured using polypropylene and are one of the best, custom solutions for drying cannabis on the market.

Mold Mitigation

Antimicrobial drying trays are highly sought after because as we’ve mentioned, mold is a crop killer. And a little mold can reproduce very quickly. Metro’s WavDri cannabis trays integrate Microban additives into each medical-grade plastic drying tray. The antimicrobial technology hinders the reproduction and spread of fungus and mold, protecting your flower while it dries.

It’s important to rotate your buds daily to allow air to reach trapped pockets of moisture, especially during the first 3-4 days of drying. Using the optional indicator plaques (or tabs) allows you to take full advantage of WavDri’s convenient rotation feature.

WavDri Cannabis Drying Tray
Using WavDri’s indicator tabs, cultivators can rotate their buds quickly and evenly, avoiding physical contact with the flower.

After inserting the tabs into place, you can stack one WavDri tray on top of another and then flip your buds. This allows cultivators to minimize physical contact with the flower, further reducing mold contamination.

Faster, More Efficient Drying

WavDri cannabis trays also feature an undulated (wave-shaped) surface that minimizes your bud’s contact with the tray. This improves air circulation around your flower, which improves drying time and also helps prevent mold reproduction.

WavDri Undulated Surface
The wave-shaped surface of Metro’s WavDri cannabis drying trays helps minimize contact with cannabis buds while improving airflow.

The Microban additive works along with the wave-shaped surface to combat the growth of mold, making WavDri a premium solution to maintaining a healthy harvest before moving your dried cannabis to the curing phase.

Maximizing Space in Your Drying Room

It’s easy to underestimate how much space your cultivation business requires for drying buds and trim before curing. Even if you choose to hang-dry your signature strains for a couple days, cannabis drying trays are the most efficient use of your drying space.

WavDri Cannabis drying trays are effective, even when placed only three inches apart from each other. This maximizes how much plant material you can dry and allows adequate room for air to circulate around the buds so you can take full advantage of the vertical space in your drying room.

How Many Trays Do You Need?

Each WavDri tray can hold a little over 1.5 kilograms of cannabis flower or buds. When determining how many drying trays to purchase, you’ll need to consider the following:

  • What is the maximum amount of harvested flower I will be drying at one time?
  • Will I be using the touchless rotation feature?
  • Do I want to have trays in reserve to use while cleaning used trays?
  • Does my cannabis operation primarily use the metric system or the imperial system? (We’re going to do some simple conversions to accommodate both!)

First, you need to know how much flower you will be harvesting by weight. After harvesting your crop, wet-trim your flower. This means you will be removing the stems and sugar leaves before you begin the drying process.

For example, if you have 5,000 lbs. of flower after trimming, that comes to about 2,268 kilograms of bud and shake. As each tray holds about 1.5 Kilos, you’ll need about 1,512 trays active in your drying room.

WavDri Cananbis Drying Tray
Each WavDri tray can hold about 1.5 to 2 kilograms of cannabis flower. If you have 5,000 lbs. of cannabis flower post-trimming, you’ll need about 1,512 trays in active use.

If you’re using the touchless rotation feature, you’ll want to double the number of trays so you can easily flip the buds every day. And if you’re a large grow facility, it’s recommended to have a set of trays at the ready. That way you can introduce a clean set of trays to your drying room when the used set gets sent to be sterilized.

Need More Help?

We hope you found this article helpful and informative. Avoiding mold, fungus, and bud rot through efficient drying is important – and we’re here to help.

If you have questions about our selection of cannabis drying trays, including our innovative WavDri trays, feel free to reach out to our team. We’re happy to help and provide additional resources and answer any other questions you may have.

2 thoughts on “Cannabis Drying Trays: What’s the Best For Buds?

  • April 6, 2022 at 6:51 pm

    Good day; my name is Francisco Padilla. I am working for Avicanna LatAm placed in Santamarta Colombia.

    I have a question for you gents. I need to understand, above you said each grow 5,000 lb of wet harvest, we will get 2,263 Kg of wet flowers. That´s mean: 5,000 lb of wet harvest… of what? mean plants grown or plants harvested? Another thing is: 5,000 lb are 2,273 kg (each 2,2 lb are a 1 kg)… almost same weight. this mean every kg of plant grown… will be a kg of flower?
    Do you have a kind of bulk density of wet cannabis flower?

    • July 11, 2022 at 1:29 pm

      Hello and thank you for your question, it’s a very good one! It’s our pleasure to clear up any confusion. After harvesting your cannabis, it needs to be wet-trimmed before using the WavDri trays. This means you’ll be removing the stems and sugar leaves from your flower before drying. In the example provided in our article, the calculations are based on wet-trimmed flower and shake (little bits of bud that sometimes break off.) This was a little confusing, so we have updated our article to help explain the process more clearly. We appreciate your feedback and hope to see you again. 🙂


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