The Best Ways to Store Rosin and Hash for Maximum Shelf Life
Fine extracts and concentrates, such as live rosin and especially full melt bubble hash, require specific storage conditions to maximize their shelf life. While this might seem obvious to many, there’s still quite a bit of debate about which method works the best. There’s nothing worse than spending top dollar on a gram of solventless only to find out that not only is it not shelf stable, but it’s lost some of its profile and morphed into a new texture. In other cases though, leaving a rosin out of a cold environment actually enhances its texture and usability. In this exclusive TerpGuide article, we’ll walk you through what the science says and exactly what to do to ensure your precious terpenes and cannabinoids stay as well preserved as possible, for as long as possible.
What Science Tells Us About Storing Rosin
It shouldn’t come as much of a surprise to most readers that even though rigorous scientific studies are being conducted in higher numbers now than ever before, our knowledge of cannabis sativa is still decades behind other major agricultural crops. One of those blind spots is in this specific topic, but there are a handful of studies that inform current best practices for storing extracts. An important study from Italy¹ that was published in 2019 weighed four different storage protocols of hashish and flower to measure their THC as well as CBD content over time under different conditions. The conclusion was definitive: neither cannabinoid degraded much after the full four year study when the product was stored at -20°C (-4°F) in airtight containers with minimal light exposure. Thankfully, that’s on the higher end of the temperature range for a standard refrigerator’s freezer, so special equipment isn’t required.
Another study² (of dried flower in this case) found that terpenes in vapor phase were shown to significantly mitigate the oxidative degradation of THC when injected into storage containers compared to samples that didn’t get the same treatment. This indicates that terpenes themselves may have an important effect on the preservation of certain major cannabinoids. Neat. Serious scientific inquiry into the preservation of volatile terpenes themselves appears to be severely lacking. While the boiling points of various terpenes are featured in almost every article on the internet on the topic, that’s just the point at which that specific terpene fully dissipates. Most of them have a boiling point between 250-350°F, but they begin volatilizing well below those temperatures.
One of the few concrete indicators we have on the topic of temperature-induced terpene evaporation is actually a non-cannabis study³ that measured terpene loss in caraway seeds. The ubiquitous terpene limonene, which is prevalent in many strains of cannabis, was tracked as a part of the scientist’s testing and experienced significant losses in seeds stored at just over 100°F compared to 77°F. Anyone who has had good live rosin knows that the delicate, floral essence of what makes it “live” is easily lost, but we’ll need to stay patient to get more detailed data on which specific terpenes are the most likely to disappear with temperature changes.
Never leave your dog, or grams of rosin in a hot car. If there are any other better studies out there that track the actual loss of specific terpenes over time under different circumstances, we couldn’t find them. What this means to us however is that most connoisseurs who swear by freezing or at least refrigerating their hash and rosin are right. This tracks with our own anecdotal experiences across many years of enjoying these products, but the way each concentrate is processed tends to have a similarly significant impact on long term quality too.
Rosin Shelf Stability and How Temperature Induces Texture Changes
One major contributing factor to how well any given rosin might stay in fighting shape over time is what post-processing methods a lab uses to create a shelf stable end product. Whipping (aeration), warm curing, and cold curing are all potentially employed in different circumstances to improve homogeneity of solventless concentrates as well as to turn rosin into a viscosity that’s workable in vape cartridges. Just about everyone who has been dabbing for long enough has had grams that come as a shatter-like texture and are hard to work with, but once left at room temperature for a day or two, will soften into a lovely badder. Most operators nowadays strive to give consumers rosin that will remain the texture the hash maker intended whether it’s refrigerated or not. When that’s not the case, it’s advisable to let the rosin morph into the desired texture, and then put it in cold storage until it’s done.
We’ll take a stand here and say that even though many live rosins are perfectly good for a while left out on your counter, if you aren’t keeping them in a proper low temperature environment, you’re letting them lose their delicate terpene profiles much more quickly. This is even more critical for full melt-quality ice water hash, because it will grease up almost instantly outside of a freezer. Even though live rosin and ice water hash when frozen or refrigerated will be somewhat less aromatic while cold, what really matters is flavor, which is much better safeguarded in this manner.
The Best Ways to Store Live Rosin and Bubble Hash
Whether you’re nursing quite a few special grams like we typically do or just want to make sure each dab of the rosin you just bought is as good as the last, there are two simple methods we suggest. Our preferred storage protocol is to skip all the fancy accessories and get airtight glass canning jars to keep your hash sealed in them between uses, which should be refrigerated or better yet, frozen. Refrigerating your solventless is a little easier though because you don’t really need to let it come to temperature before peeling off a dab or two. When it comes to frozen concentrates, it’s always best to let them sit closed for at least 15 minutes before opening to let some of the latent moisture evaporate off of the exterior of the glass and lid.
In commercial operations, large volumes of live rosin or ice water hash are pretty much always stored frozen in this exact manner before they’re grammed and packaged. New strain drops can take a while to get ready for shelves, so professional hashmakers have learned a long time ago that freezers are usually their terpenes’ and cannabinoid’s best friend. This isn’t to suggest that warm curing is a bad method (because it’s not), it’s that once you get your desired end result, the science indeed shows that temperature, light, and oxygen exposure all play critical roles in volatilizing terpenes and degrading cannabinoids.
Interestingly enough, the author received some home grown, washed, and pressed Poontang Pie from our co-founder, Cliff, over two and a half years ago. It is serving as an on-going experiment and in many ways the impetus for this article because it is still going strong and incredibly has only lost a little bit of its step in the profile department. It’s only been refrigerated, not frozen, and for convenience’s sake, is my preferred method for everything that isn’t ultra special because most grams don’t stick around for a fraction of that time. Granted this is only one particularly long term data point, but we’ve found that properly stored grams of rosin or hash can stay perfectly delectable for well over a year or in certain cases much longer when tucked away in the right cold conditions. Rosin does tend to revert to a sort of dry waxy badder consistency after a long time, but it’s still perfectly serviceable in most cases. For those extremely special strains you don’t want to let go of, freezing them in airtight glass is your best bet to retain maximum potency and flavor.