How long can cannabis last?

[BritManToo]

Glass jars at room temp, all go brown by 6 months, still usable but not at it's best.

Just for fun I vacuum packed some of my grow in Jan 2023, and put it on the top shelf of my fridge.

 

It still looks green after 2 years and 6 months, wonder what it will be like?

It's lost its vacuum.

 

[SamuiGrower]

Cannabis begins to degrade immediately from post harvest. You can slow it down by controlling the environment in which it is dried, cured and stored, but can not keep it at bay for an extended time. Degradation of flower directly affects quality and value.

 

Cannabinoids (THC, CBD, etc al.), terpenes and flavonoids degrade by light (photo-oxidation - primarily UV light), enzymes, and oxygen/air. Monoterpenes are the most volatile and begin to evaporate (volatilize) almost immediately. Chlorophyll degrades through enzymatic and microbial degradation. This is a good thing, reducing harshness and affecting the flavor in a positive way. Decarboxylation, the conversion of THCa to THC (also a good thing) occurs slowly. The conversion of THC to CBN also occurs and is an indication of “old” flower - not a good thing! A research paper I saw a couple of years back showed a linear decrease of THC and other cannabinoids over time, regardless of storage techniques used. Temperature, humidity and light are the major factors attributing to quality and purity loss.

 

On a commercial level, cannabis is viewed as a perishable crop and should be sold and consumed before any quality characteristics are compromised. For personal/hobby grows and consumption, cool, dry environments will slow down the process. Vacuum sealing and refrigeration will slow terpene loss but will not abate CBN conversion. Freezing will do the same but if the flower has more than 5-10% moisture it will not ‘look’ very good, but if it is for personal consumption, no big deal, right? A humidity pack (63%) with your flower in a sealed mason jar, kept out of direct light, in a cool place is the correct handling for those of you who enjoy connoisseurship.

 

One of my pet peeves, here in Thailand, is the handling and display of flower in dispensaries/weed shops. That pale, bleached look, that makes all flower look the same is a result of photo UV oxidation. High temperatures and humidity fluctuation certainly doesn’t help. Does your local weed shop turn off the air cons at the end of the day? Where do they store their flower when they are not open? Oversupply and poor merchandising of perishable flower is the issue. It always reminds me of an overcooked green vegetable - pale and drab.

 

i hope this was helpful.

 

[wombat]

does it still do the job?

[SamuiGrower]

11 minutes ago, wombat said:

does it still do the job?

A poster in this forum once wrote, “…..the difference between getting high on 15% THC flower and 30% THC flower is one hit! “ I found this so humorous AND so true. Lol.
 

I have smoked “vintage” hash that was several years old and yes, it still got the job done.

 

The takeaway catchphrase for those that enjoy flower: “Fresh is BEST”

[jvs]

Against every thing i see on the internet i decided to freeze my stash ,more then a year and still works fine for me.

 

[RSD1]

On 6/16/2025 at 3:44 PM, BritManToo said:

Glass jars at room temp, all go brown by 6 months, still usable but not at it's best.

Just for fun I vacuum packed some of my grow in Jan 2023, and put it on the top shelf of my fridge.

 

It still looks green after 2 years and 6 months, wonder what it will be like?

It's lost its vacuum.

 

 

TBH, the way you’ve got that bagged up there looks a bit dodgy. The whole point of vacuum sealing is to get all the air out so that when you put it in the fridge it doesn’t get damp from condensation caused by temperature and humidity fluctuations when opening and closing the fridge door. Bagged loosely like that, it leaves space for moisture to build up. If you’re serious about preserving weed long term, it’s gotta be in airtight bags with all air removed.

 

Also, there are two thicknesses of those vacuum bags: 190 micron and 220 micron. You’re using the thinner ones. In my experience, those thinner bags eventually start leaking air after a while in the fridge. Don’t know why that happens, but that’s never happened with the 220 micron ones.

 

When the high quality weed I normally use was more expensive, I used to buy larger quantities to get a discount, then vacuum seal it, and store it in the fridge for months. Even buying over 100 grams back then, it was still about 100 Baht per gram, so I wanted to keep it fresh for as long as possible. I’d double bag it with the thicker 220 micron bags, seal each one tightly, and it would stay fresh with no air leaks or condensation. I sucked out all the air with the bagging machine and the packaging way very tight to the touch. Even after six to eight months in the fridge, it was still in great shape. What I always did was take it out of the fridge and let it sit for 24 hours before opening, just to let it come back to room temperature before exposing it again to hot air.

 

That said, I don’t store it in the fridge anymore. Weed that used to cost a lot is now about a quarter of the price, so I don’t worry about keeping it so long term anymore. Now I prefer jars so the buds stay fluffy and don’t get compressed by the vacuum seal and I can easily open the jars and get a whiff whenever I like. Much more convenient.
 

I buy the large 32 oz Ball Mason jars on Lazada for around 100 Baht each and put two Boost humidity control packs in each jar. You can store 50-70 grams of weed comfortably in one of those sized jars. The Boost packs also hold the humidity at 62 percent, which prevents mold without over drying the weed, and the jars are airtight, keeping the weed fresh for months. That’s what most of the cannabis shops use to store their weed for display too. Using the jars and humidity packs, it should easily stay fresh for about six months, or longer if you don’t keep opening the jars. Heat and light will degrade it over time, so I keep the jars in a cabinet. Heat’s hard to control in Thailand, but at the prices I’m paying now, if some of it dries out too much after six months, I’ll just dump it and buy more. No point in messing around with vacuum sealing only to end up with hard, compressed buds. Long term preservation just isn’t that important anymore.

 

What I might do, though, is pick up an extra 100 to 150 grams soon, separate it into 25 gram bags, and keep that in the freezer. Not for regular use, just as a backup in case there’s ever a shortage or a price spike.

 

If anyone wants links to the mason jars, humidity packs, or the thicker vacuum bags I use, let me know and I can post the Lazada links to the sources.