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How To Store Cannabis Long-Term

There’s nothing better than harvesting a shed-load of bud at the end of a grow, but if you don’t know how to store marijuana properly, you may find that it doesn’t keep long enough for you to use it all. When exposed to the wrong conditions, weed tends to go mouldy, covered in mildew, or lose potency as cannabinoids like THC and CBD break down.

Fortunately, you don’t need any high-tech gear or scientific know-how to store weed correctly, although you may want to invest in something more appropriate than plastic baggies or your mom’s tupperware.

Why Proper Storage Is Important

Prolonged exposure to the elements can be disastrous for weed once it’s been harvested. Oxygen, light, high humidity levels and unstable temperatures all accelerate the degradation of cannabinoids and terpenes, so controlling these variables is the key to keeping your nugs fresh.

As cannabis ages, THC converts to CBN, resulting in a loss of potency. Luckily, this process can be halted – or at least slowed – by storing weed in an airtight container and protecting it from light and temperature fluctuations. Research conducted in the 1970s found that dried cannabis flower can be preserved for up to two years if properly stored. The same research revealed that exposure to direct sunlight causes THC and other cannabinoids to degrade rapidly, which is why it’s so important to store cannabis in a dark place[i].

More recent studies have examined the effect of heat on cannabis storage. Research published in 2019 found that weed kept at room temperature loses its potency in just a few months, but that long-term storage in the cold and dark keeps cannabis fresh[ii].

What we’re getting at here is that you need to think carefully about how to store weed, or all your hard work during the growing phase could count for nothing.

The Importance Of Drying And Curing

It doesn’t matter what kind of storage container you choose if you haven’t dried and cured your cannabis flower before stashing it. Failure to complete these two essential steps will leave your bud excessively moist and significantly increase the chances of your supply going mouldy.

Proper curing is also necessary to improve weed’s taste, potency and smoothness. When putting cannabis into storage, you want to ensure it’s in peak condition, otherwise, you’re bound to be disappointed when you roll up several months later.

The Best Storage Containers for Weed: Glass Mason Jars

Glass is by far the best material for keeping weed fresh, which is why so many growers choose to store cannabis in mason jars or other glass jars. For starters, these vessels are airtight, which means they’ll keep your nugs safe while preventing any tell-tale odours from escaping.

Importantly, glass won’t alter the aroma or taste of your weed. This can sometimes happen with plastic containers or metal cannabis stash jars, and no one likes metallic-tasting buds. On the contrary, keeping cannabis in glass jars allows the curing process to continue indefinitely, which means your weed should become smoother and more potent over time.

Humidity packs are an excellent investment if you plan to store cannabis in mason jars for months or even years. Most growers find a 58 per cent Boveda pack to be ideal, as this keeps the relative humidity levels in the jar within the optimum range to prevent mould from setting in.

Glass containers full of bud should always be kept in a cool, dark place, such as inside a cupboard that is not above a fridge or near any electrical equipment. Proximity to appliances that generate heat can result in temperature fluctuations, causing damage to your weed.

What About A Humidor?

There’s no doubt that humidors and stash boxes look way cooler than mason jars. Sadly, however, they aren’t the best option for long-term storage. A good quality humidor should maintain a stable humidity level, although these boxes – which are typically designed to store cigars, cigarettes or pipe tobacco – are usually made from cedar wood.

Unfortunately, the oil in cedar can damage terpenes and significantly alter the taste of cannabis. If you decide to use a humidor, be sure to buy one specifically designed for weed storage and made from a more suitable wood such as bamboo, teak or mahogany.

Always Avoid Plastic Bags

We all sometimes store cannabis in plastic bags, even though most of us know this is a terrible idea. The lack of protection provided by flimsy baggies means that trichomes are easily damaged, while weed kept in bags quickly loses its potency and flavour.

If you absolutely have to use baggies, then your best bet is to vacuum seal them and leave them in a cool, dry place. By removing all the air in the bag you can slow down the rate at which THC converts to CBN while also protecting terpenes.

Can You Store Weed In The Fridge Or Freezer?

When we talk about a cool, dark place, we mean anywhere colder than room temperature. An airtight container that is kept in a shaded spot with a temperature of 15 to 21 degrees Celsius (60 to 70 degrees Fahrenheit) should keep your pot in good nick for up to a year.

However, super long-term storage can only be achieved by freezing. Doing so can keep weed in perfect condition for years to come, although many growers advise against freezing weed as this causes trichomes to become brittle and fall off when knocked.

Ultimately, however, there’s no doubt that the freezer is the best place to store cannabis if you want to keep it for a really long period of time. To prevent trichomes from detaching, make sure to keep your weed inside a protective container and allow it to defrost before handling fully.

As for the fridge, don’t even think about it. Despite their cold temperatures, fridges are rubbish at maintaining a constant humidity level, and refrigerated pot often goes mouldy. If, for whatever reason, you have to keep your pot in the fridge, then your best bet is to store it in an airtight glass jar, with a humidity pack thrown in for good measure. Blacking out the sides of the jar can protect your precious bud from UV light and prolong its shelf-life further.

Follow these tips for proper storage, and you’ll never again have to worry about dry, mouldy or impotent weed – provided you remember what we said about drying and curing!

[i] Fairbairn JW, Liebmann JA, Rowan MG. The stability of cannabis and its preparations on storage. Journal of Pharmacy and Pharmacology. 1976 Jan;28(1):1-7. –

[ii] Zamengo L, Bettin C, Badocco D, Di Marco V, Miolo G, Frison G. The role of time and storage conditions on the composition of hashish and marijuana samples: A four-year study. Forensic science international. 2019 May 1;298:131-7. –

Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

Ben Taub