How Bubble Hash Is Rated


Viviane Schute

Cannabis enthusiast and student of the art of solventless extraction

✅ Updated 5/19/23

Bubble hash, or bubble for short, is often used as starting material for rosin production, and for good reason. Bubble hash is a solventless cannabis extract that contains higher percentages of cannabinoids and terpenes than unprocessed cannabis flowers, translating into a uniquely flavorful, pure, and potent rosin. Because bubble hash contains only trace amounts of unwanted compounds and plant particles, extractors generally achieve higher yields with bubble hash (also known as ice wax and full melt) than with dried and cured cannabis flowers.  

High yields and superb quality draw rosin extractors to bubble hash like bees to honey, but not all bubble hash is created equally. As with any rosin extraction, the quality of starting material is the main factor determining the quality of the final product, so a way to rate bubble hash as a starting material is key. The better the bubble, the better the rosin. 


 Bubbles and Melt 

In fact, not all hash “bubbles”. The bubbles, or clear mini-domes that form as the hash is vaporized on a hot surface, are only present in hash at the higher end of the quality spectrum. That said, it’s common to refer to any ice water hash extraction as “bubble”, making the rating system all the more important.  


Similarly, “full-melt” refers specifically to the total vaporization of the highest quality hash which leaves nothing behind, unlike lesser grades of hash that leave behind some residual materials after being heated. Full melt hash is often dabbed by itself, rather than being used as starting material for hash rosin. 

In solventless extraction, everything goes back to the grow. The plant genetics, its growing environment, nutrition, timing of harvest, and care in handling, drying, and curing all contribute to the overall quality of ice water extraction. Likewise, the techniques and craftsmanship used in creating ice wax determine the quality of the rosin it will produce. And not all bubble hash is created equally.    

So how is bubble hash rated? Bubble hash is rated on a scale from 1-6 stars, with 6 stars being the best of the best. Below is a breakdown of the various grades of bubble hash. 



At the low end of the spectrum, hash in the 1-star range contains the highest percentage of unwanted materials (e.g. particulate matter, dust, tiny pieces of plant material). This hash is less refined as the higher grades and is generally produced using filter screens of larger micron sizes.  

We can say that 1-star hash has no melt. It's at the very low end of quality. 


2-star can easily press with heat and pressure. 

Unlike true bubble or full melt hash, 1-2 star hash generally contains materials that stick around after being heated instead of fully vaporizing. Therefore, this hash isn’t the best for dabbing, but it does make a great hash for cooking edibles, topping over flower in a bowl, or rolling in a joint.

This cooking grade hash is generally darker in color, sometimes dark brownish and slightly emerald due to the amount of plant material it contains. 





Unlike full melt hash that completely disappears without a trace after being heated, a 3-star hash will leave small traces of leftover material after being heated for a dab. The term “half-melt” is common to describe hash in this range. This grade of hash is a good candidate for either rosin production or smoke enhancement, like mixing in a bowl of flower or a joint.  

3-star hash can be dabbed, but you won’t get a very good experience.  

That said, 3-star hash is a step up from the lower grades, since it can basically boil down into a lump when heated without any pressure. 


4-star hash is the entry-level quality of hash that is fit to dab. 4-star will rapidly boil all over inside a banger, with bubbles and clear domes everywhere, although it will leave considerable contaminants behind in the bowl.

4-star hash also makes good source material for pressing rosin. 


This grade of bubble hash makes the best starting material for rosin production and can be dabbed by itself for a great experience. 5-star hash is true bubble hash, producing mini translucent bubbles when being heated near the point of combustion. It also almost totally melts away on a quartz banger, demonstrating the purity of the material.  

5-star hash is filtered during production in such a way to collect only the full trichome heads (along with some trichome stalks), giving it an incredibly high level of purity and potency. This makes it the best choice for rosin starting material, producing high yields with stunning clarity and color. 

5-star hash melts down and creates one big clear dome when heated. Any contaminants that are within the hash gets gets pushed to the outer perimeters, creating a ring of contaminants around the resin. This ring of residual oils and contaminants is left behind in the banger, hence it's not a full-melt hash (the contaminants don't melt away). 


At the very pinnacle of quality is the 6-star hash. 6-star hash will melt almost as completely as rosin does, without ever leaving it's trichome state. This is the most pure version of hash. 

6-Star hash is great for dabbing, and it's even such a good quality that it's not pressed into rosin. But, it can make great hash for creating Piatella

Check out this great video from @jollyroger about how to test hash purity:


True full melt represents the pinnacle of cannabis craftsmanship. Creating the finest bubble hash requires an inspired level of artistry and skill, utilizing the right equipment and the right process. The best 6 star hash is hard to come by and you likely won’t find it at your local cannabis club.  

So next time you’re around some bubble hash, take some time to give it a rating. No matter where it falls on the scale, every hash has its place and can be appreciated in its own ways.  Learn more about How To Wash Bubble Hash and pickup our Bubble Wash Bags to get started!

Thoughts? Let us know by joining our secret Facebook group. Hang out with a community of like-minded solventless heads like yourself. Ask our head extractor questions, share your latest press and learn from hobbyists and experts in the industry.


What does full melt bubble hash mean?
Full melt hash refers to the finest, most pure hash that will melt completely away when exposed to heat, not leaving any residuals behind. Full melt hash is the holy grail of cannabis products, and it's not easy to achieve hash of this supreme quality. 

What can you do with lesser-quality bubble hash like 1-2 star?
You can use this hash for making edibles or infusing MCT oil for capsules. 

What is the best use for 3 or 4-star bubble hash?
3 and 4-star hash is well-suited for pressing into hash rosin.

Should you press 5 and 6-star bubble hash into rosin?
Most extractors will enjoy 5 and 6-star hash by itself and not press into rosin. True 6-star hash is a prize that can even be diminished by pressing into hash rosin. 

What can you do with the very best 5 and 6-star bubble hash?
Aging hash can take the quality to the next level, helping to enhance the flavor and make for an even smoother smoke over many years. Learn more about how this process works in our article Aging Bubble Hash 101.


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