Cannabis extraction is the essential process of isolating cannabinoids and terpenes from raw plant material to create concentrated products like oils, waxes, and edibles. Different extraction methods yield different product qualities, potencies, and uses. In this guide, we explore the top five cannabis extraction techniques — both solvent-based and solvent-free — with step-by-step processes, pros and cons, and the equipment required for each.
CO₂ Extraction (Supercritical)
CO₂ extraction uses pressurised carbon dioxide in its supercritical state to extract cannabinoids, terpenes, and other compounds. It is widely regarded as one of the cleanest and most efficient methods.
Step-By-Step Process
- Preparation: Dry and grind cannabis flower or trim.
- Pressurisation: CO₂ gas is compressed until it reaches supercritical conditions (high pressure and temperature).
- Extraction: Supercritical CO₂ is passed through the cannabis material, dissolving cannabinoids and terpenes.
- Separation: The mixture is passed into a separator where CO₂ is removed and cannabinoids are collected.
- Post-processing: The extract may undergo winterisation or distillation to purify the final product.
Equipment Needed
- CO₂ extraction machine (with compressor, extractor vessel, and separator)
- Chiller/heater unit
- Storage tanks
- Vacuum oven (for post-processing)
Pros
- Produces high-quality, solvent-free extracts
- Retains delicate terpenes with precise control
- Eco-friendly and non-toxic
Cons
- High initial equipment cost
- Complex process requiring trained operators
- Slower extraction time compared to hydrocarbon methods
Hydrocarbon Extraction (Butane/Propane)
Hydrocarbon extraction uses butane, propane, or a blend to produce potent concentrates like shatter, wax, or live resin. It’s known for excellent terpene preservation.
Step-By-Step Process
- Loading: Cannabis material is placed into a closed-loop extraction column.
- Solvent introduction: Chilled butane or propane is passed through the cannabis to dissolve cannabinoids and terpenes.
- Collection: The cannabinoid-rich solution is collected in a separate chamber.
- Evaporation: Solvent is removed using heat and vacuum to purge residual hydrocarbons.
- Post-processing: Winterisation and decarboxylation may be used for refinement.
Equipment Needed
- Closed-loop hydrocarbon extractor
- Vacuum oven and pump
- Recovery pump
- Solvent storage tank
Pros
- Highly efficient and fast
- Produces flavourful, full-spectrum extracts
- Suitable for small and large-scale production
Cons
- Flammable solvents pose explosion risk
- Requires a certified, explosion-proof environment
- Residual solvent risk if not purged properly
Ethanol Extraction
Ethanol extraction is a popular method for producing tinctures, oils, and distillates. It can be used for both cold and warm extractions.
Step-By-Step Process
- Soaking: Dried cannabis is soaked in ethanol to extract cannabinoids and other compounds.
- Filtration: Plant material is filtered out, leaving behind an ethanol-cannabinoid solution.
- Evaporation: Ethanol is evaporated using a rotary evaporator or vacuum distillation.
- Purification: Winterisation removes fats and waxes for a cleaner extract.
Equipment Needed
- Ethanol extraction unit or simple soaking containers
- Filtration system
- Rotary evaporator
- Chiller/freezer for winterisation
Pros
- Fast and effective for large volumes
- FDA-approved solvent
- Scalable for industrial operations
Cons
- Can co-extract chlorophyll, leading to bitterness
- Requires post-processing for full refinement
- Ethanol is flammable and must be handled with care
Rosin Pressing
Rosin extraction uses only heat and pressure to extract cannabinoids, making it one of the cleanest methods without any solvents.
Step-By-Step Process
- Preparation: Place cannabis flower, hash, or kief in parchment paper.
- Pressing: Insert the parchment into a heated rosin press and apply pressure.
- Collection: Rosin oozes out and is collected from the paper.
- Curing (optional): Some rosin is cured at room temperature to alter texture or flavor.
Equipment Needed
- Rosin press (manual or hydraulic)
- Parchment paper
- Collection tools
Pros
- 100% solvent-free and safe
- Easy to do at home or small-scale
- Retains high terpene content
Cons
- Lower yields compared to solvent methods
- Time-consuming for large-scale production
- Not ideal for extracting from trim or biomass
Ice Water Hash (Bubble Hash)
Ice water extraction uses freezing water and agitation to separate trichomes from cannabis, which are then dried to create bubble hash.
Step-By-Step Process
- Freezing: Freeze cannabis buds or trim for better trichome separation.
- Agitation: Mix cannabis with ice water in a bucket or washer.
- Filtering: Use mesh bubble bags to strain and collect trichome-rich water.
- Drying: Remove water and dry the collected hash using a freeze dryer or air-drying method.
Equipment Needed
- Buckets or automated washing machine
- Bubble bags (various micron sizes)
- Ice and purified water
- Freeze dryer (optional for quality)
Pros
- No chemicals or solvents involved
- Preserves full cannabinoid and terpene profiles
- High-quality hash for connoisseurs
Cons
- Labour-intensive process
- Requires careful drying to prevent mold
- Lower yields than solvent-based methods
Bonus Method: Dry Sift (Kief Collection)
Dry sift, also known as kief collection, is a traditional method that involves sifting dried cannabis through fine mesh screens to separate trichomes from the plant material. This technique is simple, clean, and ideal for those who want to extract potent trichomes without heat or solvents.
Step-By-Step Process
- Drying: Ensure cannabis is thoroughly dried to allow trichomes to break off easily.
- Sifting: Gently rub or shake cannabis over mesh screens of different micron sizes.
- Collection: Gather the fallen trichomes (kief) from a collection tray or surface.
- Pressing (optional): Kief can be pressed into hash for easier storage or consumption.
Equipment Needed
- Fine mesh screens (100–160 microns)
- Collection tray
- Scraper or card for gathering kief
Pros
- Extremely simple and cost-effective
- No chemicals or special equipment
- Produces highly potent, terpene-rich material
Cons
- Time-consuming and labour-intensive
- Less efficient yield from trim or shake
- Final product may vary in purity depending on technique
Choosing The Right Extraction Method: Key Factors To Consider
With various methods available, selecting the right cannabis extraction process depends on several crucial factors:
End Product Goals
- Want full-spectrum extracts like live resin or shatter? Hydrocarbon might be best.
- Need tinctures or distillates for edibles or topicals? Ethanol or CO₂ are optimal.
- Prefer dabbing solventless concentrates? Rosin or bubble hash are top choices.
Scale And Budget
- Small-scale/home use: Rosin pressing or dry sift offer low entry costs.
- Commercial operations: CO₂ and ethanol systems offer scalability and compliance but require high investment.
Purity And Safety
- Solvent-free methods are generally safer and cleaner but may yield less.
- Solvent-based extractions require rigorous safety measures and lab testing to ensure no residual solvents remain.
Terpene And Cannabinoid Preservation
Hydrocarbon and solventless methods typically retain the most aromatic and flavorful terpenes.
CO₂ offers a balanced full-spectrum profile but may need post-processing to match hydrocarbon flavour intensity.
Choosing the right cannabis extraction method depends on your goals, budget, and desired product. Solvent-based techniques like CO₂, ethanol, and hydrocarbon extraction are ideal for commercial operations seeking potent, refined products. Meanwhile, solventless options like rosin pressing and ice water hash appeal to those looking for purity and simplicity. Regardless of the method, each technique offers a unique balance between efficiency, safety, and product quality.
