How is Rosin Made?

Cannabis concentrates have risen in popularity over the last few years, but one form of extract has emerged as the most desirable: rosin. Not to be confused with resin – such as live resin, which is still extracted using solvents – rosin is a solventless extract that offers a full-spectrum terpene profile with unparalleled purity.

Read on to learn everything you need to know about rosin including what it is, how it’s made, and how to make rosin at home.

What is Rosin?

Rosin is a type of cannabis oil extracted using only heat and pressure, as opposed to the harsh solvents required to make other forms of concentrate like shatter. Most concentrates are extracted from the plant by stripping away the cannabinoids with solvents such as butane or CO2, traces of which inevitably remain in the final product. But rosin is prized for its purity because nothing is added or combined with the plant to produce it – the cannabinoid-rich sap is simply melted off the plant.

Rosin is also a rare example of a superior product that’s simpler to make than its lower-quality counterparts. Solvent extractions require heavy machinery and volatile chemicals, but extracting rosin can be done with something as simple as a hair straightener. One of the reasons solventless rosin is still more expensive than solvent extracts is that pressing rosin requires more manual labour, precision,  and is typically produced in smaller batches.

Rosin shares its name with violin bow rosin, which is derived from pine sap and collected in a similar way.

How is Rosin Made?

Rosin is typically produced, at a commercial scale, using a specialised machine called a rosin press which consists of two heated plates that are pressed together, producing up to 1,000 pounds of pressure per square inch. The upper limits of these machines are necessary to press rosin out of raw flower, but rosin can be extracted from kief and bubble hash as low as 300 psi.

To prepare the flower for rosination, it may be pre-pressed into a flatter shape more conducive to the final press. This prevents the flower from wadding up, and ensures a more even distribution of heat. This slim brick of flower is then inserted into a micron bag and placed into the press.

When the hot plates begin to press the flower, the rosin in the trichomes will melt and begin to flow like water which can make an awful mess. To account for this, the micron bag is itself wrapped in parchment paper with one side left open for the oil to pour out of. This is called “directional flow” or a “directional fold.”

The melted rosin is squeezed from the flower, through the micron bag, and poured out across the parchment paper where it cools. Once the rosin stops flowing, the press is released and the bag of squeezed flower can be discarded. The resulting rosin easily scrapes free from the parchment paper like wax and can be immediately smoked or stored for later.

How to Make Rosin at Home

Rosin is so simple to make that it can even be extracted at home with a few supplies. To make your own rosin, you will need a flat iron or hair straightener to apply heat and pressure, parchment paper to catch the rosin, and raw cannabis flower. You can also press kief or hash into rosin if you have some.

Begin by cutting the parchment paper into manageable squares or rectangles. Each of these squares will be folded in half and pressed between the plates of the hair straightener. It’s important to use parchment paper and not wax paper, otherwise the wax will melt in the heat and mix with the rosin, making it dangerous (if not impossible) to smoke.

When pressing rosin with a hair straightener, the ideal temperature is between 180° and 230° F. Lower than this will not be hot enough to separate all the rosin, and higher than this will begin to damage the terpene content of the oil, affecting flavour and potency. That said, lower temperatures will require more pressure to separate the rosin, so if you’re having trouble squeezing all that oil free, go ahead and turn up the heat. If your hair straightener or iron is too hot, then you can let the temperature rise then fall a few seconds before pressing the cannabis.

Fold a single piece of cannabis flower between a sheet of parchment paper and flatten it a little with your fingers. When the hair straightener is at the right temperature, place the flower between the plates and press down as hard as you can. After only 5-10 seconds, the process should be complete. Release the plates and unfold the parchment paper. Ideally, the flattened cannabis flower will slide free leaving the oily rosin behind on the parchment. This pure, full-spectrum rosin can then be scraped free, dabbed, and smoked!

Rosin vs. Resin

Rosin should not be confused with live resin, which is another full-spectrum cannabis concentrate. Similar to rosin, live resin is also prized for its more complete terpene profiles which are preserved by flash-freezing the plant before extraction. But ultimately, live resin relies on chemical solvents to separate the cannabis oils from the plant material, whereas rosin does not.

Summary

Rosin is a cannabis extract produced without the solvents required for other concentrates like wax or shatter. Traditional concentrates are extracted by flushing solvents like butane or supercritical CO2 across the plant, but rosin is instead extracted using only heat and pressure. The heat melts the cannabinoid-rich resin and the pressure squeezes it from the plant where it is then collected like the juice from a berry.

On a commercial scale, rosin is collected from a rosin press machine composed of two metal plates that can generate a thousand pounds of pressure. But rosin can be harvested at home as well using a hair straightener and parchment paper (not wax paper!). To collect your own rosin, simply fold some cannabis between a piece of parchment paper. When the hair straightener is between 180 – 230 F, press the cannabis as hard as you can between the hot plates. After only 5-10 seconds, release the plates. When done correctly, the trichomes on the bud’s surface will have melted and stuck to the parchment paper as rosin.

Rosin is not the same as live resin. Live resin originates from a fresh-frozen plant to preserve a fuller terpene-profile, but it is still extracted using chemical solvents. Other concentrates may be called “solvent-free” after a solvent purging process, but rosin is the only hash oil concentrate that is truly solventless from beginning to end.

Frequently Asked Questions

What is so special about rosin?

Rosin currently stands alone as the only solventless hash oil. While other concentrates like bubble hash and kief can be collected without solvents, they are not exactly oils, and are still more often smoked than vaped. But rosin offers a full-spectrum extract with no additives that boils away clean every time.

What is rosin and how do you use it?

Rosin is a cannabis concentrate similar to wax or shatter and is consumed the same way, typically using a dab rig.

Is rosin better than shatter?

Rosin is purer than shatter because it is extracted without any solvents or additional chemicals. This simpler extraction method, using only heat and pressure, also results in a full-spectrum extract that shatter typically cannot match.