The Cannabis industry is booming, with many companies emerging to meet the rising demand for safe and legal cannabis. To stay competitive in this growing industry, cannabis extraction laboratories and processing units need a plan and decide how to obtain cannabinoids from the cannabis plant safely and in high purity.

If you’re looking to make cannabis extracts, you might have heard of Rosin, Agitation, Water extraction, and other methods. You might be wondering, What is Rosin? Why is it used? Or, What are some other extraction methods that I can use? Most importantly, what’s the difference? This article answers some of these questions.

There are various methods to separate the active components of the Cannabis plants from undesirable substances like waxes and fats. Primarily, there are two methods of extraction for cannabis – solventless method (solvent-free) and solvent-based method.

• Solventless extraction methods don’t use chemical solvents like alcohol, butane, or CO2 but instead employ various agitation techniques and machines that utilize low temperatures and pressure to cut off or melt the trichomes of the cannabis plant.
• Solvent-based extraction techniques use a volatile chemical to dissolve the trichomes and the remaining cannabis plant matter, resulting in powerful cannabis oil. After separation, the unwanted substances are removed by purging. This creates a concentrated product, free of any undesirable plant substance. [1]

Solventless Cannabis Extraction

An increasing number of people are seeking out cannabinoid derivatives made by a non-solvent (or “solvent-less” method). They are safer to consume since they are produced more naturally. Whether it’s true or not is a delicate issue that is constantly debated in the cannabis industry.

Solvent-free or solventless separation is, in fact, not “extraction” at all but, in reality, “mechanical separation.” This implies that the cannabinoid was not removed from the plant matter but was separated using physical force.

Hand-pressed hashes, developed several decades ago, were among the first kinds of solvent-free concentrates. Solventless extraction methods do not employ chemical solvents to harvest the plant’s natural oils. Instead, they utilize different agitation techniques and equipment that use pressure and heat to remove it from its plant. [1]

Dry sieve or Agitation

Dry sieve extraction creates a powder-like Kief with around 35-50% THC potency. Dry-sieving is accomplished by crushing dried cannabis against an abrasive screen. This separates the trichomes, which then fall away. The final product could be further processed into hashish or combined with dry flowers. This process, though, is slow but is simple and labor-intensive at the same time. This causes the dry sieve extraction from being a popular choice for Cannabis extraction at an industrial scale.

The effects of agitation can tear the trichomes in cannabis flower buds. For example, dry sift kief, a collection of cannabis-derived trichomes, is separated from cannabis with different screen meshes or sieves. Using mechanical or manual methods, the sieves break down the resinous trichomes gathered in the lower part. Kief can create a wide range of cannabis-related products, such as press hash to enhance joint potency as well as a dry herb.

Ice Water extraction, another extraction method by Agitation, involves submerging cannabis in a mix of water and ice in bags made of mesh. After Agitation with cold water, it allows for easy breaking of the trichomes, which are then pushed into the bottom of the bags to be collected later. The methods can harvest the collected cannabinoids ranging from 50 – 70 percent THC.

The advantages of agitation extractions are:

• Safe: For Health-conscious customers, using solvent-free products gives the consumer security for the products being pure and safe as no external chemical is used in the process. Furthermore, there is no chance of toxicity or harm to the body because of the absence of flammable solvents.
• Accessible: Dry sieving and ice extraction methods are reasonably priced for commercial and home production. [1] [2]

Water extraction

In this extraction method, Cannabis is put in ice water and stirred. This separates the trichomes from the other plant matter. After being removed from the cannabis plant, a set of screens is employed to remove the liquid.

This process yields cannabis extracts of THC levels ranging from 50 to 70 percent.

Water extraction yields approximately the same amount of THC as a dry sieve; however, it also relies on the strength of the base substance. The process begins with placing the marijuana plant into the mesh bag, soaking it in ice water, and after that, stirring it to knock the trichome out. The trichome is then cleaned through a set of screens and then let to settle before collecting and drying the product. It is commonly called bubble hash or water.

The technique of Hot water extraction can also be used. This method uses water in its supercritical form. High pressure and temperature keep water supercritical throughout the extraction process. It is mainly used to extract CBD- rich Cannabis extracts.

Similar to dry sieving, this method is not easy to scale, and also the potency is difficult to control.

Advantages-

• It is an eco-friendly method of cannabis extraction that uses water.
• Pressurized Hot water extraction recovers the polar and semi-polar bioactive compounds from the plant material.
• This method exhibits a high rate of selectivity in Cannabis extraction. [2] [3]

Rosin extraction

Rosin extraction uses the process of heat and compression to extract oils and the rosin. The conditions of high temperature and low pressure are not feasible for this process, so the ability to retain terpenes is limited. A typical pneumatic press can avoid high-temperature fluctuations. It exerts low temperatures and keeps the terpenes safe while preserving their original properties.

In this extraction method, low temperatures and pressures are employed for melting and squeezing the rosin out of plants. This procedure is similar to the way olive oil is produced. In the production process, extraction equipment breaks the cell walls and releases oil from the Cannabis plant. This oil can then be processed for consumption.

The resultant sticky, dark and potent oil is known as Rosin. Rosin is consumed in a dab or as an infusion into many products like edibles, tinctures, and topicals. Live Rosin uses frozen fresh buds to give an enhanced flavor and scent.

On a smaller scale, cannabis users can use a hair straightener and some buds to extract the resin with the lowest pressure and  temperature setting of the hair straightener. While it will not yield as potent extracts as the commercial extraction of Rosin, it will offer an extremely rich and concentrated product.

Rosin pressing has many benefits:

• Simple: Rosin pressing is relatively less challenging to accomplish than solvent-based extractions.
• Secure: There is no risk of explosions at home or the lab.
• Flexible: The producers can change the temperature and pressure to make solvent-free extracts that come in various consistency and colors.
• Quality: The best concentrates are produced by pressing Rosin. [1] [2]

Conclusion

As the cannabis industry evolves, alternative extraction methods have become popular because they effectively reduce costs and facilitate product manufacturing. These methods are very efficient and use little-to-no solvent. This means that these solventless extraction methods are safe and clean, but choosing the proper way to work best with your needs is essential.

References:

[1]- https://blog.lunatechequipment.com/the-5-most-common-cannabis-extraction-methods

[2]- https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-021-00087-9

[3]- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7144126/