The cannabis industry has long tried to keep the content of the product as pure as possible without the use of extraction solvents like butane and ethanol. The problem with using these ingredients in the extraction process is the adulteration of desirable compounds like cannabinoids and terpenes. To improve the experience of users, the industry is shifting towards a more natural and pure extraction method, solventless extraction.
The concept is not new and has been used for centuries for hard-pressed hashes. The benefit of solventless extraction is that it can preserve the plant’s natural essence without the use of potentially harmful chemicals.
In this comprehensive guide, we will explore solventless extraction methods, including the various techniques, their benefits, and the factors that influence the quality of the final product.
A solvent is a chemical used as a catalyst to extract compounds from cannabis. While solvents facilitate the process of extraction, they degrade the purity of cannabis compounds. As the name suggests, the solventless extraction method obtains cannabis concentrates without the use of chemical solvents.
The solvent extraction process relies on physical or mechanical means to extract the desired compounds from the cannabis plants. The goal is to maintain the integrity of the natural components of cannabis, including cannabinoids, terpenes, and flavonoids, without introducing any external chemicals. This method replaces substances like CO2, propane, and butane with natural forces such as heat, pressure, or cold temperature to strip away the desired compounds from plants. This fundamental difference offers a purer and safer end product.
Common Types of Solventless Extraction Techniques
There are several solventless methods to extract cannabis compounds. Here, we will explain the most commonly used solventless extraction methods:
Ice Water Hash Extraction
Also known as bubble hash or bubble hash, the extraction method of ice-cold water and agitation is used to separate trichomes from the plant material. As the ice water has freezing temperatures, it makes trichomes (fine outgrowths of plants) brittle and detach easily. As trichomes contain most of the plant’s cannabinoids and terpenes, this method can extract the purest compounds without solvents.
In this solventless extraction process, cannabis material is submerged in ice-cold water and agitated. The frozen trichomes break off and sink to the bottom. The mixture is then filtered to collect the trichome heads, passing it through several screens. The resulting product, ice water hash, is highly potent and pure.
The ice water extraction method is preferred because it preserves the terpene profiles, and the end product has minimal plant contamination.
Rosin Press Extraction
Rosin press extraction is another popular solventless method that uses a combination of heat and pressure to squeeze the oils out of cannabis flower, hash, or kief. Rosin press has two metal plates arranged in a vice grip. The brick of hash is put between the metal plates, which are then heated and squeezed under high pressure. The extracted material, known as rosin, is a potent concentrate that retains much of the plant’s original flavor and chemical composition.
This solventless extraction method is quick and efficient because it can preserve a wide range of cannabinoids and terpenes-flower, hash, or kief.
Other Techniques
1. Dry Sift: In this method, dried cannabis is put over a series of fine mesh screens and gently agitated to separate trichomes from the plant.
2. Hand-Pressed Hash: It is an ancient technique where cannabis is rubbed between hands to create a ball of resin.
Benefits of Solventless Extraction
The purity and integrity of the content are not the only benefits of solventless extraction methods; there are several more benefits.
1. Purity and Quality
Manufacturers can provide unparalleled purity and quality in the final product without any chemical solvents. Solventless extraction ensures that the extracted concentrate contains only the natural compounds present in the cannabis plant. Products manufactured with solventless extraction more accurately represent the plant’s original chemical profile, including its full spectrum of cannabinoids and terpenes.
It is evident in the superior flavor and aroma of the extracts. The pure quality of such a delicate terpene profile gives consumers a quality entourage effect – the synergistic interaction between various cannabis compounds that may enhance therapeutic benefits.
2. Health and Safety
Without any harmful chemical solvents, the final product has no risk of residue chemicals. This has more profound effects on medical cannabis patients or health-conscious consumers who have concerns regarding introducing additional substances into their bodies.
For producers, solventless extraction methods minimize the risks of handling volatile solvents such as propane and butane. This makes it possible to maintain safer facilities. Additionally, solvent extraction methods use simple equipment, typically requiring less stringent safety protocols than solvent-based systems.
3. Environmental Impact
As there are no chemical components in solventless extraction, there is no chemical waste to discard or harmful fumes released into the atmosphere. Also, there is no need for their production, transportation, or disposal of chemicals, which can contribute to a reduced carbon footprint. Most solventless methods, such as ice water hash extraction, use minimal resources and produce little to no waste. Additionally, solventless products require less packaging due to their stable nature, potentially reducing plastic waste.
Critical Factors Affecting Solventless Extract Quality
To get the best product from the solventless extraction method, the following factors must be micro-managed:
1. Raw Material Quality
As there is minimal interaction with any other ingredient, the final quality of solventless extracts depends largely on raw material quality. High-quality, well-cured cannabis flowers rich in trichomes will yield superior extracts compared to lower-grade material. Factors such as the plant’s genetics, growing conditions, harvest timing, and post-harvest handling all contribute to the overall quality of the raw material.
Strains that have high resin production and are cultivated through proper techniques to maximize trichome development are best.
2. Extraction Techniques
The extraction technique utilized significantly impacts the quality of the final product. The actual impact of the technique depends on the method, as each has its own set of variables that can affect the outcome.
For instance, in the ice water hash, solventless extraction method, factors like water temperature, agitation time, and filtration method influence the purity and yield. In the rosin press method, temperature, pressure, and duration of press affect the quality and quantity of the extracted rosin.
3. Equipment and Tools
Finally, the quality and precision of the equipment used in solventless extraction directly influence the end product. For example, for best quality output in ice water hash extraction, the quality of filtration bags and the effectiveness of the washing machine or vessel used for agitation are crucial. The same goes for the precision of temperature control and the even distribution of pressure across the plates in the rosin press method.
Producers using purpose-built equipment can get better yields, higher purity, and more consistent results.
Comparing Solventless vs Solvent-Based Extraction Methods
To better understand how the solventless extraction method compares to solvent-based methods, we have to look at both methods’ differences, quality, and effectiveness.
1. Differences in Process
The fundamental difference between solventless and solvent-based extraction is how the desired compounds from the plant material are extracted. Solventless methods rely on physical forces like pressure, temperature, or mechanical agitation, while solvent-based techniques use chemical solvents to dissolve and extract the target compounds.
Solvent-based extraction methods usually involve soaking or washing cannabis material with a solvent (e.g., butane, CO2, ethanol). Then, the solvent-cannabinoid mixture is separated from the plant material. The solvent is then evaporated to extract the concentrated extract.
In contrast, solventless methods skip the chemical dissolution step entirely, relying instead on physical separation techniques.
2. Quality and Yield
Unsurprisingly, the yield quality of solventless extracts is superior due to their purity and full-spectrum nature. The final product is more flavorful and aromatic because the method can better preserve the plant’s original terpene profile.
Solvent-based methods produce a lesser quality yield but can achieve extremely high purity levels, especially when isolating specific cannabinoids. Additionally, solvent-based methods generally have high yields due to their large-scale operations.
Another difference is that their chemical process solvent-based methods can efficiently extract cannabinoids from lower-quality inputs. However, solventless methods are more dependent on the quality of the starting material and may have lower overall efficiency.
3. Cost and Efficiency
Solventless equipment is often less expensive and requires fewer safety measures, making it more accessible for small-scale producers. Due to more straightforward raw materials, solventless methods generally have lower ongoing costs.
Solvent-based systems may have higher operating costs but can process larger volumes more quickly. However, the labor cost of solventless extraction can be higher due to its labor-intensive requirements, especially for methods like ice water hash.
In terms of efficiency, solvent-based methods are more efficient as they have high throughput. Solventless techniques, on the other hand, can be more efficient in preserving the full spectrum of the plant’s compounds.
How to Perform Solventless Extraction at Home
If you are enthusiastic about solventless extraction at home, these are the steps you can follow for making a rosin press using a hair straightener:
- Gather materials: Cannabis flower, parchment paper, hair straightener, collection tool
- Preheat the hair straightener to around 300°F (150°C)
- Place a small cannabis bud (0.5-1g) on folded parchment paper
- Press the parchment paper between the heated plates for 3-7 seconds
- Apply firm, even pressure
- Remove and unfold the parchment paper
- Collect the extracted rosin using a dabber tool
- Repeat with fresh parchment paper and cannabis as desired
Tips and Best Practices
- Use high-quality, properly cured cannabis
- Experiment with different temperatures and pressure
- Use fresh parchment paper for each press to maintain high purity
- Begin with small batches to get hold of the technique
- Always work in a well-ventilated area
Advanced Solventless Extraction Techniques
The field of solventless extraction continues to evolve, with several exciting innovations emerging. Here are some advanced solventless extraction techniques being used.
Ultrasound-Assisted Solventless Extraction
This technique uses ultrasonic waves to agitate the plant material in an ice water bath, potentially increasing the efficiency of trichome separation without the need for aggressive mechanical agitation.
Enzyme-Assisted Solventless Extraction
Enzyme-assisted extraction uses food-grade enzymes to break down the plant cell walls, making the cannabinoids and terpenes more accessible for extraction through mechanical means.
Hydraulic Cold Press Technology
Advanced presses that combine controlled pressure and low temperatures for superior extracts are used to improve the efficiency of the traditional cold press method.
Supercritical CO2 Solventless Extraction
The supercritical CO2 solventless extraction method uses carbon dioxide in supercritical conditions, accelerating the dissolution and extraction of cannabinoids and terpenes. Producers use this method as it can precisely target specific compounds.
Future Directions of Solventless Extraction Techniques
The industry is working on more efficient methods to improve the extraction of cannabis compounds. One futuristic approach is Cellular Deconstruction Technology (CDT). This method utilizes physics instead of chemicals or heat for solventless extraction.
The method involves breaking the cell walls of trichomes using 16 million joules of energy. During the process, the temperature never exceeds 90°F. Hence, the final product obtained is of the finest quality.
Safety and Compliance Considerations
While solventless extraction is generally safer than solvent-based methods, following proper safety and compliance protocols is crucial.
Handling and safety requirements
- Use heat-resistant gloves when handling hot equipment
- Ensure proper ventilation, especially if the raw material is terpene-rich
- Keep production work areas clean and dust-free
- Regularly inspect and maintain all equipment
- Follow proper electrical safety guidelines for powered equipment
Regulatory compliance
- State and federal licenses and permits are necessary for extraction activities
- Adhere to local zoning laws and building codes
- Comply with product testing and labeling requirements
- Maintaining proper record-keeping and traceability
Root Sciences and Solventless Extraction
Root Sciences, a leading provider of extraction technology for the hemp and cannabis industry, is facilitating the solventless extraction revolution by offering cutting-edge equipment and solutions. The company’s WT-MICRO, WT-CRAFT and WT-2000 line of cannabis solventless extraction equipment enhances the efficiency and quality of solventless processes.
Using advanced hardware, Root Sciences’ equipment is designed to address common challenges in solventless extraction, such as maintaining consistent pressure and temperature control. Using their equipment, producers can achieve improved yield, enhanced preservation of terpene profiles, and increased efficiency.
Conclusion
In the cannabis industry, solventless extraction methods offer a path to purer, more natural concentrates. Here, we have discussed how vital starting material quality is in determining the final product through the solventless method, the diverse range of techniques available, and ongoing innovations and future potential in solventless extraction.
As solventless extraction is increasingly essential for producing high-quality, full-spectrum concentrates, companies like Root Sciences are offering state-of-the-art equipment to embrace these methods and deliver cleaner, purer, and more natural cannabis concentrates to consumers.
