We have a lot of resource articles on this site — and some of them attract two very different types of readers.
This article on “marijuana packaging” is a good example.
Some readers are interested in finding out the best way to store their weed. For example, can they package it in certain types of bags and freeze it? Can they keep it in the bags or containers it came in, or do they have to transfer it to a better type of packaging?
Other readers are in the retail end of the cannabis business, and they may be interested in new or improved marijuana packaging techniques that could better protect and preserve their product.
Let’s take care of both groups. First, we’ll look at the best practices for packaging weed for distribution and sale; that will give us a jumping-off point to talk about how to store your flower at home.
The History of Marijuana Packaging
You probably know that cannabis was legal for sale in America for quite a while. It wasn’t until the passage of the Marihuana Tax Act (sic) in 1937 that the sale and use of weed essentially became illegal under federal law.
Since cannabis could be sold in pharmacies back then, pharmaceutical companies had to package it, and the pharmacists had to store it.
The companies did a pretty good job. Most used airtight containers were made from tin, which protected the bud from sunlight and the outside air. Those are, of course, the same general guidelines that dispensaries use today, even though they no longer use tin cans.
Druggists, however, generally kept their supplies in ceramic jars. Since that was well before the development of the Internet, we have no way to know how buyers felt about the quality of their marijuana after it had been sitting on the shelf at the mercy of light and air — but it’s not difficult to guess.
During the cannabis prohibition era, the popular rediscovery of weed was well-timed; it was in the 1960s, the same time that baggies were invented. The two weren’t exactly a marriage made in heaven but rather a marriage born of convenience.
Ziploc bags seemed to be an ideal way to package marijuana. They were just the right size to hold an ounce (or less) of flower, and one explanation for the term “a zip of weed” — meaning an ounce — is that “zip” was derived from “Ziploc.” (The other explanation is that the “z” came from the abbreviation for ounce, “oz.”)
As the decades passed, it became evident that packaging marijuana in a transparent bag that didn’t provide a 100% airtight seal wasn’t the best idea. And as legalization began arriving in various states, producers and providers found new, better ways to package and store their products. Improvements have followed ever since.
The primary considerations were the ones we’ve mentioned: keeping light and air away from the herb. Temperature and moisture were also important factors.
Here’s where state-of-the-art marijuana packaging stands today.
Cannabis Storage and Environmental Conditions
Before we list the types of materials commonly used to package marijuana products, let’s quickly list the environmental issues that can hurt weed’s quality.
- Light: All light, but particularly the sun’s ultraviolet rays, causes cannabis to degrade. Most importantly, it eventually turns psychoactive THC into non-psychoactive CBN. An opaque container that blocks light is crucial.
- Air: Excess exposure to oxygen does much the same thing to weed. It also causes the terpenes in cannabis to oxidize, ruining the bud’s flavor and aroma.
- Humidity: Too much relative humidity (more than 65%) greatly increases the likelihood that marijuana will grow mold. Too little, and it gets dry, brittle, and nasty.
- Temperature: High temperatures are likely to increase humidity levels in a storage container. Low temperatures cause the weed to dry out and trichomes to fall off; freezing your weed for later use is a very bad idea.
That explains most of the reasons why baggies are the wrong way to go about packaging and storing marijuana. They let light and air in, and they’re conducive to creating humid conditions. There’s one more: the bags are prone to building up static electricity, which can fry the bud’s trichomes when the bag is opened, and the static is discharged.
So it’s pretty clear that baggies are out. What’s in?
Modern Marijuana Packaging
Dispensaries have conflicting issues to deal with. They want to package their products in ways that best protect them, but they also want customers to be able to see what they’re buying.
Here’s how the best retail outlets handle their packaging.
Glass jars are terrific for storage. If they have the right type of lid, they can be sealed air-tight, which also keeps out extra moisture and makes them smell-proof. They also have enough room to prevent the flower from getting cramped or crushed. Jars made from medical-grade silicone are also common.
Opaque jars, though, are a problem for consumers who want to actually see the product. Most dispensaries now use labels that obstruct most light from getting in but contain a see-through window allowing customers to inspect the cannabis that’s inside.
Many vendors now sell their flowers in Pyrex tubes, which have most of the same advantages as glass jars but in a smaller size.
No, not plastic baggies. We’re talking about Mylar bags, the same ones used to package many food items. They don’t conduct static electricity, can be vacuum sealed if desired, and are available in both opaque and see-through window styles. Some suppliers even replace the oxygen in the bag with nitrogen to ensure freshness.
Vendors like them because they don’t require as much space for storage and display, and customers like them because they’re easy to transport.
Marijuana concentrates are often packaged in polystyrene (a substance like Styrofoam), acrylic, or medical-grade silicone containers because the sticky substances won’t adhere to them. Edibles are usually sold in tubes or resealable food-grade bags. Pre-rolls are most often sold in small tubes or bags.
Marijuana Packaging Methods vs. Home Storage
The same general approach that a vendor uses to package their cannabis makes perfect sense for buyers once they bring their weed home.
It should be kept in airtight containers, which prevent light from reaching the marijuana and lockout airflow. Opaque glass jars that can be sealed tight are the best choice, baggies are the worst, and the container shouldn’t be too large since that will leave too much air inside.
The flower should be kept in an environment right around room temperature, without excess humidity. And putting the stash jar in a dark closet or cabinet is a smart additional precaution.
Does that mean you should transfer your weed to a different container as soon as you get it home? Not necessarily.
If your marijuana is packaged in a sealable glass jar or tube, you probably only have to cover up the see-through window with tape or wrap the jar in a towel. If it’s in an airtight Mylar bag, leave it there until the first time you’re ready to smoke up; you can keep it there later on, too, if the bag seals tightly.
Otherwise, getting a suitable stash jar that will protect your precious weed for the long term should be job #1 — even before your trip to the dispensary.
Marijuana Packaging: FAQ
Q: My dispensary sells weed in plastic bottles, sort of like medicine bottles but with hinged tops. Are they a good place to keep cannabis?
A: Not for the long term, even if they’re completely opaque (and most aren’t). There’s the same static electricity issue that can crop up with plastic bags, and they don’t fully seal out air. Even worse, some plastic is made with BPA, an industrial chemical linked to potential health issues, which can leach out of the bottle and into your flower.
Q: Are humidors or “odor-proof” stash bags good choices for home storage?
A: Two things to know about humidors: they’re expensive, and most are specifically designed for cigars. Tobacco humidors are the wrong way to go; they’re usually made from cedar wood, whose oils can hurt weed’s flavor, and they normally maintain humidity levels that are too high for marijuana. If you want to spend the money on a humidor designed to preserve weed, it’s a good choice. Most odor-proof stash bags are fine if they seal tightly.
Q: How do you control humidity properly?
A: The best alternative is to use small, inexpensive humidity packs that go right into the stash jar or weed container and keep the relative humidity relatively stable. Boveda is the brand that most growers and connoisseurs rely on.
Fairbairn, J. W., Liebmann, J. A., & Rowan, M. G. (1976). The stability of cannabis and its preparations on storage. Journal of Pharmacy and Pharmacology, 28(1), 1-7 .