Hash enthusiasts and solvent extract heads clash from time to time. Two different categories of extracts are separated by physical process and culture. Because of this, there are fine lines in the nomenclature to define various products. For example – a certain phrase only applies to one category, but what is full melt hash and why doesn’t it apply to solute extracts?

What is full melt hash, the star system, and why does it exclude extracts?
Photo courtesy of Frency Cannoli.

What defines hash from a solvent extracts?

Frenchy Cannoli is a name well recognized in the hash community. Before he passed into trichome paradis during summer 2021, Frenchy developed a chart of the different concentrate categories. Traditionally speaking, the difference between extracts and hash is based on process; after all, water is a solvent. A concentrate is no longer hash once its trichomes (THCa, THC, or other cannabinoids) are chemically dissolved or mechanically crushed. Structurally, a trichome consists of a resin gland encased in a waxy head, and if the resin is removed from its shell, it is a solute rather than a hash (suspension.)

Water dissolves chlorophyll, sugars, and agricultural salts — the unwanted polar compounds — but it does not dissolve THC. Alcohol and alkanes instead dissolve the non-polar cannabinoids and resins. With hash, cold water and agitation simply help lift trichomes away from the less wanted polar plant substrate. From there, the two mediums can be separated, collected as solids by mechanical filtration, and then gently pressed.

What defines hash from a solvent extracts?
Frenchy Cannoli (pictured) was known for curing hash in organic cellophane to allow terpenes to diversify and even polymerize into a dynamic profile. Photo by Warren Bobrow.

Half and full melt: A hash scale

It should be noted that an odd bit of misinformation floats around hash circles, mostly due to colour remediation (CRC) salespeople. Contrary to some arguments, however, colour is not a golden rule for solventless hash or the star system. Final purity is more accurately rated by the way hash melts, but of course, that’s not without debate. Regardless, there is a generally accepted definition of full versus half melt hash.

If hash is vaporized on a screen over high-temperature quartz (or titanium) and 50 to 75% of the hash melts, it is considered a half-melt in many circles. Half-melts can be great and typically more cost-effective, but they do not bode well for dabs. But if more than 75% of the hash vaporizes, liquefies, or sublimates then it is considered a full-melt hash. Beyond this, hash quality has also been broken down into a star system.

full melt hash
Six star, 73u Deadhead OG vaporized with only oil remaining, zero char. Photo courtesy of Bret Maverick.

Does the old star system hold any ground?

Hash with a three and four-star rating is typically a half-melt; whereas, a five-star hash will be a full melt. Six-star hash is rather an elusive icon consisting of highly pure, intact trichomes. Some carbon will almost always be left behind after vaporizing a solventless cannabis concentrate. That said, if less than 5% of the material by weight remains after vaporization, the hash can genuinely be revered as a true six-star.

rosin
Photo courtesy of @Leftcoastc.

Do you agree that rosin is a solventless process of extracting cannabis, but that it cannot be categorized by a star system? And what about limonene hash oil?

In any case, we have half and full melts, and a star system to judge hash quality. That sounds organized, but it is based on trichome structure after separation and the quantity of residual material (carbon) after vaporization. Quality becomes more complex when accounting for the variety of compounds many refer to as cannabis’s full spectrum.

Have you ever had the pleasure of dabbing six-star concentrates? Let us know your thoughts on the definition of full melt hash in the comments.

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