What is Bubble Hash?
While the world of modern cannabis extracts has a dizzying array of textures and techniques to explore, bubble hash (also known as ice water hash or ice water extract) was the first major leap forward in extract making practices to emerge out of traditional middle eastern style hashish. While all extracts are either refined or concentrated cannabis resins in one form or another, bubble hash has recently experienced a true renaissance since the invention of modern rosin making techniques.
Bubble hash is essentially isolated trichomes which have been collected from cannabis plants using cold water and ice, which are then filtered by micron size and dried for consumption. For those that don’t know, the reason it’s called “bubble” hash is because it bubbles when heated and vaporized as opposed to denser hashish which tends to simply melt instead. There is some debate whether dry sifted trichomes can also technically be known as bubble hash, but we tend to believe that sift is in its own separate category. Divided into a variety of quality grades known as the star system, bubble hash is graded from one to six stars depending on its color, aroma, and most importantly how much residue is left when vaporized. The very best bubble hash is known as six star, or “full melt”, because it leaves very little to no residue behind when vaporized, proving its purity. Bubble hash was originally made with trim and dried flowers, but more recently processors have made the transition to using fresh frozen cannabis in order to make a truly “live” bubble hash that preserves the full complexity of strain at maturity. While this technique is dominant today, we’ll see later in this article why this may slowly start changing as new information emerges about terpene changes in dried cannabis.
Bubble Hash History
The person that really put the term bubble hash on the map was the eponymously named Bubbleman (aka, Marcus Richardson), who is largely credited with creating and marketing the original premier filtration bags used in the process. While Bubbleman’s “Bubblebags” were the first to popularize this technique, Sadhu Sam is largely credited with the invention of the original technique, described in detail by Robert Clark, and then made into an early commercial product created by Mila Jansen. Here’s a quick timeline of how it went down:
- In 1988, an article appears in High Times Magazine which was Sadhu Sam’s water extraction guide
- Fast forward 10 years, and in 1998 Reinhart Delph patents the process and Mila Jansen releases the very first ice water hash bags, later renamed Ice-O-Lator® bags
- Six months later, in March of 1999, Bubbleman improves significantly upon early bag designs and releases his branded Bubblebags
The next major innovation in this process came with the introduction of freeze drying into the process, which made it become considerably less time intensive to dry bubble hash after washing than ever before. Prior to this technological advancement, bubble hash was carefully air dried over about a week in humidity and temperature controlled environments, but mold was always a threat. If dried it too quickly many terpenes in the hash volatilize, leaving a lower quality product. Conversely, if dried too slowly, mold has enough time to develop and ruin the entire batch. Thankfully, this is largely an issue of the past as commercial operators today use freeze dryers to both shorten the dry time dramatically (about 24 hours of dry time) and significantly improve product quality as well. Commercial processors nowadays usually have a few of them on deck at all times, with Harvest Right’s pharmaceutical units and Labconco’s FDry-8L being the most popular choices.
What Bubble Hash is Used For
In the past, bubble hash was primarily used to add potency to smoked flower as an upgrade over older styles of bricked hash. In today’s markets, it’s most often used as the precursor to make top shelf live rosins and live rosin cartridges. Bubble hash offers an incredibly wide variety of applications, but is especially versatile for cannabis processors using the higher 5 star or 6 star grades. This is due to a couple factors, including their extremely high cannabinoid and terpene content compared to lower grades as well as their more delicate cuticle structures, make them ideal for lower pressure and temperature rosin pressing. All tiers of bubble hash are useful to businesses though as even lower quality grades are a great choice for use in tinctures and edibles.
But what determines the ultimate quality of your bubble hash? This relies entirely on the qulaity of flower that was used to make it – only the very, very best cannabis will yield full melt, 6-star hash. On top of this, in mature markets especially, fresh frozen is the starting material of choice to make bubble hash so that it’s “live”, which results in a more flavorful, terpene-rich end product (not to mention it retails for a lot more). We’ve gone pretty deep into how to make great bubble hash in other articles so make sure to check them out if you’re looking for tips and tricks.
Ultimately what you can do with your bubble hash will depend on what approximate star rating it possesses, which in turn is dictated by the quality of starting cannabis used. You can achieve any grade of hash with either live or dried cannabis, but it tends to be easier to get the most premium quality ice water hashes with live, fresh frozen material. The reasoning behind that is unless the cannabis was dried and cured perfectly, its chances of becoming a full melt-level product are much lower. With fresh frozen, as long as the cannabis is very high quality at harvest, it has a better chance to reach into the 5 and 6 star range in the final bubble hash.
6 Star/Full Melt
Typically sold as-is as a connoisseur grade product to be dabbed for maximum enjoyment, although much of what is labeled as full melt is actually 5 star bubble hash. Six star is also used to make the very best live rosin, which can then be further refined into solventless sauce and diamonds or solventless rosin cartridges.
The line between 5 and 6 star hash is faint to non- connoisseur-level hash smokers, but it is there. Most live 5 star bubble hash is used to make live rosin, which can then be refined into the same products listed above, but some is also sold as-is too because it’s still great to dab. Anything less than 5 star and the likelihood of making a great rosin cartridge or high solventless terpene extract is reduced considerably.
Once you drop below 5 star bubble hash, your options start becoming a little more limited. 3 and 4 star bubble hash can be great for live rosin, but they tend to make more of a mid-shelf or economy grade hash rosin at that point. These grades of hash are also perfect for hand pressed or bricked hash for topping bowls, which is making a comeback after being bubble hash’s go-to form in the 90s and early 2000s.
Finally, at the very bottom of the scale you have your 1 and 2 star bubble hashes, which are best suited for edible applications and are most often made from trim or older cannabis. While these grades won’t pass muster for shelf-sold concentrates, color and aroma scarcely matters when it’s been decarboxylated and put into something tasty with the right formula.
One very important thing to keep in mind is that the fine details while making bubble hash, especially when using fresh frozen, make all the difference. The best hash artisans use only RO filtered water and ice while washing in a cold room for maximum terpene preservation. Great quality bubble hash also becomes sticky almost immediately at room temperature, so everything from collection to packaging should be done in a chilled environment if possible.
“Live” vs. “Dried” Hash
In order to make live rosin, live bubble hash must be used. But that doesn’t mean that you can’t make incredible ice water hash with only fresh frozen, there are just some elements that each hash maker and business will have to consider for their market in order to decide which route to go with each batch. As a matter of current best practice, pretty much all of the best solventless concentrates are being made from fresh frozen cannabis that is harvested and stored in a freeze as quickly as possible. While this has traditionally thought to have retained the full profile of the cannabis plant at the time of harvest, if cannabis is dried and cured properly, some terpenes volatilize but others may actually become more prevalent interestingly enough.
According to one of the better assessments on the matter by Eybna from 2021, certain terpenes are perhaps especially prone to volatilizing, while others may become more concentrated during the drying process for cannabis flowers. Take a close look at the chart below from their study. While some terpenes such as beta-myrcene and alpha-pinene were in higher concentrations 3 week prior to harvest, alpha-humulene and especially beta-caryophyllene actually rose in concentration after one week of drying and one week of curing. What the researchers concluded is that when cannabis is dried, it leads to an increase in sesquiterpenes at the expense of monoterpenes, but each strain will behave differently in this regard depending on its original terpene composition at the time of harvest. Many hash makers we’ve spoken to have discovered similar results based on their own testing efforts over many batches, but as of this writing, this is still fairly new territory for many. This study only looked at a single cultivar in a fairly narrow time period across three interval terpene concentration tests, but it does provide telling clues for processors who might be considering mixing it up by washing dried material batches in addition to all of their live SKUs.
As the author of the paper masterfully put it, what “live” really is and why it’s so desirable to consumers is that it’s the plant’s unique metabolic fingerprint, which is quickly changed or even sharply degraded post-harvest depending on the skill of the cultivator when drying takes place. As we’ve noted in other articles [link to Cannabinoid/Terpene Cold Chain blog], terpenes are not the only organic compounds affected by time and storage conditions. For example, THC degrades quickly into CBN if not properly stored in cold, airtight and light tight conditions. This tricky balancing act of deciding which type of material to use can only be determined through experimentation, and ultimately accepting the fact that not every batch of bubble hash using dried cannabis will come out as good as their live counterparts, or vice versa. As time goes on, we expect to see more hash makers adding specialty dried strains to their solventless bubble hash making repertoires when the terpenes of that particular cultivar make for a unique experience. If you’re looking to experiment with dried vs. fresh frozen bubble hash comparisons, you’ll need to make an investment in terpene tests with your local laboratory to figure out exactly which ones are going to be your best bet.
Connoisseurs looking for premium solventless options may find specialty non-live bubble hashes or rosins appealing if the correct strains are used, but what strains those may be are probably ones with high sesquiterpene concentrations to begin with since they could improve after drying. What is clear, however, is that just like most scientific topics in cannabis, a lot more research remains to be done. If your lab or operation is looking to make bubble hash, or make bubble hash better, make sure to contact our experts today for a free consultation. We offer custom training and equipment packages for businesses big and small, so if you’ve been curious about solventless, let’s talk!