Cannabis Storage Explained
Considering a tolerance break? Or need to store your weed for later for some other reason?
Obviously, you’ll want to keep it fresh and potent. And above all, avoid wasting it.
But how long does weed stay good for anyway? And how do you store it?
Well, cannabis comes in so many forms nowadays that there’s no single easy answer. Which is why we’re going to cover both of those ‘how’ questions in detail below.
We’ll cover each of the main types of cannabis — flower, concentrates, edibles, tinctures, pre-rolls, vape cartridges — how to store it, how long it’ll last, and how to tell if it’s gone bad.
But first, a couple of common questions about the ‘why’.
Does weed get better with age?
Up to a point. And that point is reached just before you buy it.
Much like tobacco, cannabis flower goes through a curing process. Curing usually takes around two weeks. However, depending on the strain and the desired flavor profile and CBD/THC balance, sometimes it’s done for longer.
Partly, curing is done to remove some of the plant’s natural moisture, so that it’s smokeable and stores for longer.
But the other purpose of curing is not entirely unlike maturing cheese or fine wine.
Curing brings out the flavor — and maximizes potency (during the process, more THC-A breaks down into actual THC).
However, the point is, you really don’t need the cannabis equivalent of a wine cellar. By the time it reaches your hands, it’s already done maturing.
Does weed expire? Why storage matters
Unless it gets too moist and mold develops, cannabis doesn’t expire, as such. It just gradually loses flavor and potency.
Cannabis contains hundreds of cannabinoids (complex chemical compounds) and terpenes (the aromatic compounds that give it flavor) which break down with exposure to oxygen, light or heat, and over time. Mostly, cannabinoids break down into simpler but significantly less psychoactive forms. Some of which, however, do have their own therapeutic properties.
Perhaps most significantly to your smoking experience, when it breaks down, THC turns into CBN. A cannabinoid with a famously sedative effect.
(Though if you’re smoking as a sleep aid, that may not entirely be a bad thing.)
How to store every form of cannabis and how long each will keep
To maintain potency and flavor when storing cannabis (in any form), there are four key environmental factors you’ll need to pay attention to:
- Light exposure: Avoid it!
- Humidity: Keep relative humidity at between 59% and 63%.
- Exposure to air: Avoid/minimize!
- Temperature: Keep it stable and relatively low — ideally, below 70°F.
Exactly how you’ll need to address those four variables, though — and how many of them — will vary, depending on what form of cannabis you’re storing
And on your local climate — if you live somewhere hot and/or humid, you’ll have to take more care.
Now, on to the specifics…
How long does bud / flower stay good for?
Studies have found that, in ideal conditions, flower can stay in top condition for 6 months and remains pretty flavorful and potent for up to a year.
After that, it starts to lose more and more flavor and potency the longer you store it. Relative to its original levels, on average, THC content falls by:
After 1 year: 16.6%
After 2 years: 26.8%
After 3 years: 34.5%
After 4 years: 41.4%
Even then, if it’s been stored well, usually it’s still smokeable. (In fact, in 2008, 2,700-year old weed was discovered that still contained THC!) It just won’t be a great smoke.
As for how to tell whether weed is no longer smokeable, look for: white mold, mildew, fuzz, discolored spots, sour or rotten odors. If it looks or smells a bit off, it almost certainly is.
And definitely should not be smoked! Moldy weed can make you very ill.
How to store bud / flower
The best way to store flower is in an airtight glass or ceramic jar (almost full), kept in a cool, dark place.
Unlike certain woods or metals, glass and ceramics don’t impart or absorb any flavor. And unlike some plastics, they don’t contain anything toxic (e.g. BPA), carry static (which breaks off trichomes) or ‘sweat’.
Mason jars or purpose-made weed storage jars are both ideal.
In addition, try to keep the temperature below 70°F and the relative humidity at between 59% and 63%.
To check humidity, you can use a hygrometer (some jars even have one in the lid).
But the easiest humidity control solution is simply to add a Boveda humidity pack to the jar. Unlike silica gel desiccant packs, which will only dry out your weed, these both absorb and release moisture to keep conditions ideal.
Finally, don’t keep your buds in your fridge.
It might sound like the perfect place to keep things dark and cool. But frequent opening and closing of the door causes temperature fluctuations, which in turn can cause condensation to form in your weed container and cause mold to form on your weed.
The freezer’s not ideal, either. Mold can form during defrosting. And freezing damages the (THC-rich) trichomes.
How long can you keep concentrates (oil, resin, wax, etc.)?
When creating concentrates, the original cannabis is processed to leave nothing but the plant’s concentrated flavor and potency. No plant matter or impurities.
A big side-benefit of this is that the remaining lipids and sugars are much more stable than raw or cured plant matter. They break down much slower than flower.
Which means that, with a little care, concentrates can easily be kept for a year or two.
If in doubt, check the expiry date. Most concentrates bought from a dispensary will have one.
How to store concentrates
According to the study linked above, exposure to air and light are the single biggest factors in concentrates losing potency.
So, we’d generally recommend airtight glass jars.
However, for some concentrates — and for shorter term storage — medical grade silicone is the better option. It’s not airtight, but some concentrates will stick to glass.
Either way, plenty of concentrate jars are available for the purpose.
And, again, keep them somewhere dark.
Unlike for flower, the fridge is your friend. And for long term storage, concentrates can be frozen (see the above link).
Finally, always avoid touching your concentrates with your fingers. Use dab tools (or similar), instead, to avoid introducing any impurities.
How long do edibles keep?
Here’s the simplest answer: Check the expiry date.
Most good edibles should come with a ‘Best By’ date on the pack.
Otherwise, adding cannabis really doesn’t make a difference to shelf life. So just ask yourself, ‘How long would this food normally stay good?’
That said, to maintain potency, avoid exposure to excess light, moisture, heat and air.
How to store edibles
That said, keep your edibles cool, dry, out of direct light and in something airtight. Just like any other cannabis consumable
Unlike storing flower, a fridge would be fine. Even ideal, for many of the available edibles.
How long does a pre-roll joint stay smokeable?
Indefinitely, if you don’t mind a bad smoke. But the weed will be past its best within a few weeks.
Once it’s been ground, weed dries out quicker than while still in flower form.
And rolling paper offers little protection from environmental factors.
So long as there are no signs of mold (e.g. dark spots), though, even an old joint should still be smokeable. It’s just going to smoke faster and harsher, and be less potent and more sleep-inducing, the older it is.
How to store pre-rolls
Ideally, store your pre-rolls in something airtight to keep out oxygen and moisture. Then store that somewhere cool and dark.
A Mason jar or weed storage jar, in a drawer or cupboard, is the best option. Or an airtight stash box.
That will slow down the drying out and breakdown of cannabinoids and terpenes as much as possible. Storing for a few months should be possible.
For very short term storage (a week or two), a Ziploc bag or Tupperware should be fine. Or the packaging it came in, if you bought it rather than rolled your own.
How long can I store cannabis tinctures?
Tinctures come in many forms, so the best answer is usually to check the expiry date. That said, most last extremely well. Alcohol-based tinctures can last years or even decades, if unopened.
How to store tinctures
Basically, you just need to avoid light and heat and keep out air.
So an airtight opaque bottle (often the one it came in) stored somewhere cool.
For an opened bottle, the fridge is ideal.
How long do vape cartridges keep?
When stored well: 6 months to a year, easily. The cartridge contains cannabis concentrate. So there’s no plant matter to degrade.
However, the compounds in the oil will still break down eventually.
As well as light, heat’s the major contributing factor here. Avoid leaving cartridges in the car on a hot day, for instance.
When vape oil’s gone bad, you’ll notice color change (it should be light yellow to amber); the oil may be less clear, thicker, sludgy; crystals may form on the side of the cartridge.
If you’re not sure and decide to chance it anyway, you’ll notice a bitter or sour taste, and probably cough more.
It won’t harm you. But if it’s got to that point, it’s just not worth the smoke anymore.
How to store vape cartridges
Cartridges are already airtight, so humidity’s not a factor. But as usual, somewhere cool and dark is best.
Too much exposure to light or heat and the oil will turn brown, and terpenes and cannabinoids will break down.
For travel, a protective case is a good idea, even if you’re just carrying cartridges in your pocket. Body temperature can easily exceed 70 degrees Fahrenheit, the temp at which THC starts to degrade.
Top tip: If you have a cartridge in your vape pen, ideally store the pen upright. So the oil’s already sitting at the bottom of the cartridge ready for the next time you use it.
However, ideally, cartridges should be stored separately. With the metal plate in contact with the battery, a small amount of power draw and heating does take place over time, speeding up degrading.
How long does weed stay good: Final thoughts
Hopefully, we’ve given you everything you need to know to store your weed in primo condition, for as long as you might need.
The short version: Avoid exposure to excess light, air, humidity and heat.
However, things don’t always go to plan…
If you finally tackled your kitchen cupboards during the pandemic, you’ll know exactly how easy it is to forget stuff once it’s been squirreled away.
So, here’s one last tip...
What to do with old weed that’s past its best
Assuming there are no signs of mold, you could still smoke it…
Whatever potency and flavor remains will be extracted and preserved in the process.