Concentrates
Solventless Extraction: The Purity of Process
Solventless extraction is a chemical-free method that utilizes physical processes like heat, pressure, or agitation to extract cannabinoids and terpenes from cannabis plants. Unlike solvent-based methods, which rely on chemicals such as butane or ethanol, solventless techniques preserve the purity of the plant, resulting in concentrates rich in flavor and potency. These methods are highly sought after by cannabis enthusiasts who prefer a natural, clean product without the need for solvent purging.
Rosin Extraction vs. Hash Extraction
Rosin Extraction: Rosin is created using heat and pressure to extract cannabinoids and terpenes from cannabis flower, hash, or kief. This solventless process avoids chemicals, making it clean and natural. Heat melts the trichomes and pressure pushes the concentrate out, resulting in a potent, terpene-rich product.
Hash Extraction: Hash is made using ice water or dry sifting to mechanically separate trichomes. In ice water extraction, cold temperatures cause the trichomes to break off, which are then collected and pressed into hash. It’s another solventless method but relies on cold rather than heat.
How Heat and Cold Work in Extraction
Heat: In rosin extraction, controlled heat melts the trichomes and helps extract cannabinoids without solvents. Too much heat, though, can degrade the terpenes and cannabinoids.
Cold: Cold temperatures are crucial in hash extraction to harden trichomes and make them brittle, allowing them to break off from the plant matter. Ice water is commonly used to isolate these trichomes in bubble hash production.
Types of Solventless Extraction
1. Rosin Pressing
Process: Rosin extraction is simple yet effective. Cannabis flower, kief, or hash is placed between heated plates, and pressure is applied to squeeze out the valuable oils. The combination of heat and pressure melts the trichomes, releasing the cannabinoids and terpenes in their purest form.
Molecular Level: On a molecular level, heat liquefies the trichome heads—the resin glands that contain the plant’s cannabinoids and terpenes. Pressure forces the liquid through the plant material, separating the oils without breaking down unwanted components like chlorophyll or plant fiber.
Common Equipment: Rosin presses are the most common equipment used. These machines are equipped with adjustable heat plates and pressure settings to optimize the extraction process for various starting materials.
2. Ice Water Extraction (Bubble Hash)
Process: Bubble hash is created by submerging cannabis in ice-cold water. The cold temperature makes the trichomes brittle, and gentle agitation helps them detach from the plant. The trichomes are then collected using fine mesh screens, or micron bags, which filter the trichomes by size.
Molecular Level: The ice water extraction process works by hardening the trichomes so that they can break off from the plant material without damaging other compounds. Because trichomes are more fragile than the rest of the plant, they separate easily under agitation.
Common Equipment: Bubble bags (micron bags) with specific pore sizes, stirring equipment, and cold water are the tools of the trade. The micron size of the bag determines the purity of the collected trichomes.
3. Dry Sifting (Kief)
Process: Dry sifting involves mechanically separating trichomes from the plant by shaking cannabis over fine screens. As the plant material is agitated, the trichomes fall through the screens, resulting in kief—a highly potent form of cannabis concentrate.
Molecular Level: Like ice water extraction, dry sifting relies on the fragility of trichomes. As the cannabis is gently sifted, the trichomes break away from the plant, falling through screens that filter them based on size.
Common Equipment: Sifting screens or sieve boxes with varying micron sizes are used to collect the trichomes. The screens allow smaller trichomes to fall through while filtering out larger plant material.
Common Equipment Used in Solventless Extraction
Rosin Presses: These machines use heated plates and adjustable pressure to extract oil from cannabis flower, hash, or kief. The heat melts the trichomes, while pressure forces the oil out of the plant material.
Micron Bags (Bubble Bags): These are fine mesh bags used in ice water extraction to filter trichomes by size. The bags come in various micron sizes (e.g., 25u, 160u), with smaller microns capturing finer, purer trichomes.
Sifting Screens: Used in dry sifting, these screens have varying pore sizes to filter trichomes. As the cannabis is agitated over the screens, trichomes fall through the holes, creating a collection of kief.
Micron Level and the "u" in Hash Extraction: What Are They?
Micron levels, denoted as "u," refer to the size of the mesh pores in extraction bags or screens. The size of the micron level determines what passes through the mesh, and in cannabis extraction, this refers to the trichomes. A lower micron level (e.g., 25u) means smaller pores and finer filtration, often resulting in purer, more refined concentrates. Higher micron levels (e.g., 160u) allow for larger particles to pass through, which may include more plant material.
Micron Levels Explained for Budtenders:
Smaller Micron Bags (25u-45u): Capture smaller, finer trichome heads, often resulting in the highest-quality hash with fewer contaminants. These are typically used for top-tier bubble hash or rosin pressing.
Larger Micron Bags (90u-160u): These allow larger trichome stalks and sometimes plant material to pass through. The hash from these bags may have more contaminants but can still be used for lower-grade concentrates or edibles.
Budtenders can explain to customers that lower micron levels typically mean a higher-quality product because they capture only the purest parts of the trichomes. Products labeled with specific micron sizes (e.g., 90u full-melt) are indicators of the refinement and quality of the extract.
The Rosin Process
In rosin extraction, selecting the correct micron level is essential for creating high-quality concentrates. Here's a deeper look into the process before and after choosing micron levels for rosin production:
Pre-Extraction Steps
Material Selection: Start with high-quality cannabis flower, trim, or hash. Fresh frozen material is ideal for maximizing terpene preservation in rosin.
Ice Water Washing (for Hash): Cannabis is washed in ice water, causing trichomes to break off and collect in various micron screens (typically 25u–160u). Smaller micron bags (25u–45u) catch finer trichomes, yielding higher-quality hash, while larger microns (90u–160u) capture less refined trichomes mixed with plant matter.
Post-Wash (Hash):
After collecting the trichomes from different micron bags, the hash is air-dried or freeze-dried. This produces bubble hash or full-melt hash, depending on quality. Once dry, this hash can then be pressed into rosin.
Rosin Pressing (Solventless)
Press Setup: The hash or cannabis flower is placed inside a filter bag (usually between 25u to 160u) depending on desired quality.
Smaller micron bags (25u–45u) are used to yield purer rosin with minimal contaminants.
Larger micron bags (90u–160u) are often used for flower pressing or when a broader range of trichomes is acceptable.
Heat & Pressure: The material is placed between heated plates of a rosin press. The heat melts the trichomes, and the pressure pushes the concentrate out of the bag.
Temperature & Pressure: Lower temperatures (160–200°F) preserve terpenes but yield less, while higher temperatures (200–240°F) create more yield but may degrade some terpenes.
Collection: Once the rosin is pressed, the resulting concentrate is collected. Depending on the temperature and time during pressing, the rosin can vary in texture (e.g., budder, sap, or shatter-like).
Post-Extraction Steps:
Curing: Some producers may choose to cure rosin to improve its flavor and consistency.
Storage: Proper storage in a cool, dark environment is essential to prevent degradation of the final rosin product.
In short, selecting the appropriate micron level is a crucial step that directly impacts the purity and quality of the final rosin product. Smaller micron bags capture finer trichome heads, while larger microns allow for a broader, less refined product
Influence of Starting Material on Cannabis Extraction
The starting material plays a critical role in determining the quality, potency, and yield of a cannabis extract. Here’s how different types of starting material affect the process:
Shake: Loose, fallen leaves and small buds collected during trimming. Shake can still contain trichomes but tends to be less potent, resulting in lower-quality extracts with fewer terpenes and cannabinoids.
Trim: The sugar leaves, small leaves coated in trichomes, trimmed off the buds. Trim is often used in lower-grade extractions like distillate because it contains fewer cannabinoids than flower.
Popcorn Nugs: Small, underdeveloped buds that are more potent than trim but less desirable than full-sized buds. They offer a middle-ground option for extraction, often resulting in decent quality concentrates.
Nugs: The full-sized, dense cannabis buds. Nugs are packed with trichomes and terpenes, making them the ideal choice for high-quality concentrates like live resin, rosin, or premium hash.
Key Influence of Starting Material
The potency, terpene profile, and yield of the concentrate largely depend on the amount of trichomes present in the starting material. Higher-quality material, such as nugs or even popcorn buds, typically leads to richer, more flavorful extracts with higher cannabinoid content. In contrast, shake and trim may result in lower-grade concentrates with fewer cannabinoids and less complex terpene profiles. Starting with premium flower ensures a better final product, especially for solventless extractions like rosin, where no additional refinement can mask lower quality starting material.
What Makes a Good Washer in Solventless Extraction
A "washer" refers to the cannabis material used in ice water hash extraction (commonly for bubble hash or rosin). A good washer is plant material that has the right combination of trichome structure, freshness, and cultivation practices, yielding a higher amount of clean trichomes after being agitated in ice water. The goal is to collect mature trichome heads with minimal contamination from plant material.
Trichome Maturity: Well-developed trichome heads are key. Immature trichomes result in low potency, while overripe trichomes can degrade and affect quality.
Freshness: Fresh-frozen cannabis (flash-frozen after harvest) is ideal because it preserves the trichomes' integrity and terpene profile.
Resin Content: A good washer has a resin-rich surface, meaning it’s loaded with trichomes that can easily break away during the agitation process.
The Jar Test: How It’s Performed and What It Reveals
The jar test is a quick pre-extraction method used to assess the resin potential of cannabis material for solventless extraction, especially for rosin. The process involves:
Steps:
Select a small sample of cannabis flower or trim.
Place the sample in a sealed jar with ice-cold water.
Gently shake or agitate the jar for a short time (1-2 minutes).
Let the jar settle and observe how much resin collects at the bottom.
What’s Happening at the Molecular Level:
The agitation causes the brittle trichomes to break away from the plant material, and the cold water hardens the resin, allowing it to separate and sink.
Trichomes consist of waxy heads that house the majority of cannabinoids and terpenes, and cold temperatures preserve the integrity of these compounds.
Good Yield vs. Poor Yield:
Good Yield: A higher amount of visible trichomes at the bottom of the jar signifies a good washer with a higher resin content, which indicates a strong potential for a high yield during extraction. The trichomes should appear clean, golden, or amber and relatively intact.
Poor Yield: If very few trichomes collect at the bottom or the resin appears dark and contaminated with plant material, it indicates a poor washer that may not yield well. This could be due to low trichome density, over-dried material, or poor cultivation techniques.
Signs of a Good Washer
Clean Trichomes: Clear, golden trichomes at the bottom of the jar indicate high-quality resin.
Low Contamination: Minimal plant material in the jar after the wash shows that the material can release trichomes cleanly without excessive contamination.
In conclusion, a good washer, paired with the jar test, can help identify the best cannabis material for solventless extraction. The right balance of freshness, resin quality, and trichome maturity will lead to better yields and higher-quality rosin.
Why Solventless Extraction?
Solventless extraction techniques produce some of the cleanest, most flavorful concentrates on the market. Without the need for chemical solvents, the resulting products are prized by consumers who want the full spectrum of cannabinoids and terpenes in their natural form, free from chemical residues. Whether it's rosin, bubble hash, or kief, solventless methods are favored by purists and connoisseurs alike for their ability to preserve the essence of the cannabis plant in its most unadulterated form.