As cannabis enters the mainstream and consumers become savvier about the different ways of consuming the product, rosin has become an increasingly compelling option for consumers who want to completely avoid exposure to residual solvents. Rosin is a solvent-less concentrate extracted with the application of heat and pressure.

Rosin’s Popularity is on the Rise

A 2018 Drug Alcohol Dependence study by researchers from Thailand, Ohio, New York, and Massachusetts reports that in the states that have legalized cannabis, there is a substantial increase of tweets lauding the concentrate as a safer, more natural cannabis extract than more conventional alternatives. That’s about the extent of the research on the safety and efficacy of rosin. But it doesn’t take too much deductive reasoning to understand why the concentrate is exploding in popularity. Here’s why:

• It’s solvent-less. That means that harsh, toxic chemicals are not used to extract it from cannabis plant matter.
• It’s easy (and safe) to make. For the most part, all you need is an iron and some weed.
• It’s potent. Just like any concentrate, it contains trace plant matter and an abundance of cannabinoids and terpenes.
• It’s versatile. You can dab it, sprinkle it on flower, or use it to make an edible.

How To Make Rosin

The technology to make rosin is so simple, it makes the entire solvent-based concentrate industry look a little silly. Rosin can be made with any form of cannabis plant matter including flower, kief, or bubble hash. All you need is to apply heat and pressure to melt the terpenes and cannabinoids out of the plant matter. The everyday consumer can do this at home with a hair straightener, parchment paper, a micron filter bag, a collection tool, and heat-resistant gloves.

Source: Wikileaf

1. If you're using plant matter, break down your nugs. Make sure that your weed isn't too moist or too dry, or you won't get the results you're looking for. If you're using bubble hash or kief to make your rosin, you'll need to put it in a micron filter bag.
   Source: Wikileaf
2. Set the temperature on your straightener. You can always go back and repress your material if you don't get enough the first time, so make sure you start out at a low temperature and work your way up.
   Source: Wikileaf
3. Place your micron bag or your loose flower between two pieces of parchment paper. Make sure that you only put as much cannabis on the parchment as will fit between your hair straightener. Make sure to leave some extra parchment paper all around the straightener to catch runoff rosin. Otherwise, it's going to get all over your straightener.
   Source: Wikileaf
4. Press the parchment paper between your straightener. The amount of time you need to keep your weed pressed in the straightener really depends on both the strain and quality of your weed, so you'll need to experiment a couple of times to find the sweet spot for your weed. That being said, if you're going much over 30 seconds with no results, you probably to raise the temperature on your straightener and try again.
   Source: Wikileaf
5. Remove the parchment paper from your straightener. If you have a low yield, repeat the process, but remember that you're only going to get so much depending on the quality. So keep your yield expectations reasonable.
   Source: Wikileaf
6. Use a dabber to collect your rosin. Stretch, pull, and twist it like taffy, and store it in a container away from light.
   Source: Wikileaf

Not only is rosin totally achievable with these easily accessible materials, but it can also be produced in a matter of minutes. BHO, on the other hand, can take days to process since it must be purged of residual solvent before it is ready for consumption.

Rosin’s popularity is not just among consumers. The cannabis industry has seen a rise in the development of portable and commercial-scale rosin presses. The former can be used by a typical consumer interested in making their own rosin. The latter can be used by retailers.  These industrial presses apply an immense amount of pressure at a low heat so that the cannabinoids are extracted without destroying the terpenes. The result is a flavorful, potent, and residual solvent-free concentrate.

Solvent-less Concentrates Like Rosin Might be Safer to Consume and Safer to Make   

There is very little evidence examining the effects of residual solvents on cannabis consumers. There is this 2019 Respiratory Medicine Case Reports study that described an acute respiratory failure and lung injury suffered by a previously healthy 18-year-old woman after dabbing butane hash oil (BHO), a waxy concentrate extracted with butane. In her case, the researchers theorized that residual BHO degraded into methacrolein and benzene, butane and terpene byproducts that have caused acute lung injury and swelling in animal studies.

Other non-cannabis related studies investigating human exposure to butane offer evidence that cannabis users can extrapolate from. A 2005 Journal of the American Chemical Society study found that butane is mildly toxic by inhalation and can cause drowsiness. A 2012 American Conference of Governmental Industrial Hygienists report found that inhaled butane caused drowsiness after 10 minutes at 10,000 ppm. These reports (and many others like it) demonstrate that butane is not necessarily lethal, but can be slightly hazardous when inhaled for a sustained period of time at a high concentration.

While all cannabis processors will claim to purify their concentrates of residual butane, the reality is that there will likely be trace amounts of the solvent left if it was used during the extraction process. Rosin bypasses this risk entirely because it does not require the use of a solvent. Not only does this avoid the risk of inhaling butane, it avoids the risk of blowing up a garage during the extraction process. Butane is mildly risky for consumers, but it is a very dangerous substance to deal with for amateur extract technicians who may not understand the solvent’s volatility. Rosin, on the other hand, is made with simple technology and without exposure to highly flammable solvents.

Can Rosin Go Bad?

Rosin is a concentrate, and like all concentrates, its cannabinoids and terpenes can and will degrade over time. The trick is to store your concentrate in a way that reduces its exposure to light, air, excess humidity, and heat. Separate your rosin into amounts you would use in one session. Place each section in parchment paper. Place that parchment paper in a size-appropriate glass container. Store that container in a dark room at room temperature.

Some people opt to vacuum seal their concentrates in a freezer bag and store it in the refrigerator or freezer. The problem with this strategy is that it can expose your concentrates to the excess humidity inherent in fridges and during the thawing process. When stored properly, the cannabinoids in rosin will likely begin to slowly degrade at around the 2-week mark. However, if you are a frequent cannabis user, you won’t have to worry about your rosin losing its punch.

How Much Does Rosin Cost?

The cost of rosin will depend on the dispensary you visit let alone the state you’re in. However, $20-$30 is likely to get you a gram. If you’re interested in making rosin yourself and have $200-$400 to spare, you can purchase a portable rosin press from Amazon or Walmart. You can make high-quality rosin this way for a much cheaper price than what you would find at a cannabis retail store. Given the simplicity of the process, it might be worth the initial high cost of the equipment.