Cold Water Extraction

Revealing the Power of Cold Water Extraction

by | Apr 16, 2024

Cold Water Extraction

Written by Jessica McKeil

Jessica McKeil is a cannabis writer and B2B content marketer living in British Columbia, Canada. Her focus on cannabis tech, scientific breakthroughs, and extraction has led to bylines with Cannabis & Tech Today, Terpenes and Testing, Analytical Cannabis, and Grow Mag among others. She is the owner and lead-writer of Sea to Sky Content, which provides content and strategy to the industry’s biggest brands.

The Historical and Modern Journey of Hash Production

Humans have used hash for spiritual and medicinal reasons for thousands of years, with archaeological evidence stretching back to the Iron Age. A notable discovery was made by the Journal of the Institute of Archaeology of Tel Aviv University in May 2020, which published findings of hash use from the Judahite Shrine of Arad in Israel, dating back thousands of years.

Traditional hash production methods have been preserved over the centuries, especially in regions like the Himalayas and Morocco, where producers still rely on manual techniques involving sieves and screens to separate the trichomes from the plant material. This method is reminiscent of the 8th-century hash production techniques found in Israel, highlighting a long-standing tradition.

In contrast, the 1990s saw the introduction of a modern twist to hash production by Frenchy Cannoli, a celebrated hashishin, who popularized the use of ice-cold water for extraction. This method has since gained traction for its ability to produce high-quality hashish and cannabis concentrates. It’s particularly favored for making edibles and tinctures, offering a cleaner and more potent extract than traditional methods involving heat or solvents.

What is Cold Water Extraction Hash?

Cold water extraction (CWE), also known as ice water hash, is a popular method for extracting THC and other cannabinoids from cannabis plants. This solventless extraction method involves using ice-cold water to separate the trichomes (the resin glands that contain the highest concentration of cannabinoids) from the plant material.

How Does Cold Water Extraction Work?

Ed Rosenthal, the grandfather of cannabis cultivation and extraction techniques, explained that cold water extracts rely on “water, ice, and agitation.” When subjected to these ingredients, the microscopic trichomes caking the surface of the flower become extremely brittle. During agitation, these trichomes break off into the ice water wash. Trichomes are fat-soluble and, therefore, are easy to collect with fine mesh bags. Once dry, the loose cannabinoid trichomes are pressed into balls, bricks, or sold as powdered kief-type products.

Coldwater extraction, as the name suggests, is a process that operates in temperatures at or below the freezing point. This protects many more of the most sensitive compounds than is possible under solvent extraction conditions.

Unlike other extraction techniques, cold water extract is simple and affordable enough for small-scale producers to adopt. But as the commercial market has begun to shift away from petrochemicals toward more natural production standards, even commercial facilities like CaliHash are working with cold water extraction these days.

As Calihash explains, a cold water extraction “fundamentally respects the integrity of the original cannabinoid profile.” Under most extraction processes, extreme heat and pressure often come into play. These harsh conditions destroy or alter the most volatile cannabinoids and terpenes. In some cases, the extraction goes through such high temperatures that the final product is nearly devoid of a terpene profile.

Benefits of Using Cold Water Extraction for Cannabis:

Solventless

Unlike other extraction methods that use solvents, cold water extraction is a solventless method. This means that no chemicals or solvents are used in the process, making it a safer and more natural option.

High-quality product

Cold water extraction preserves the delicate terpenes and cannabinoids found in the trichomes, resulting in a high-quality and potent product. This method also allows for a full spectrum extract, meaning it contains all of the cannabinoids and terpenes present in the plant material.

Versatile

Cold water extraction is a versatile method that can be used with different types of cannabis plants, including flowers, trimmings, and even keef (the sticky resin that accumulates on scissors or grinders when breaking down cannabis). This makes it a great option for using up all parts of the plant, reducing waste.

Easy and cost-effective

Cold water extraction can be done at home with basic materials and does not require expensive equipment. It is also a relatively quick process, making it a cost-effective option compared to other extraction methods.

Large Scale Cold Water Extraction Systems

Commercial cold water extraction systems are commonly used by professional cannabis extractors to produce high quality products on a larger scale. These systems typically consist of large washing machines or tumblers that agitate the plant material and separate the trichomes using cold water. Here are some key steps in how the pros use a commercial cold water extraction system:

  • Preparation: The cannabis plant material is first dried and cured before being placed in the extraction machine. This helps to remove excess moisture and improve the quality of the final product.
  • Agitation: The plant material is then agitated in a washing machine or tumbler filled with cold water. This helps to break off the trichomes from the plant material and mix them into the water.
  • Filtration: The mixture of cold water and trichomes is then passed through a series of filters, usually made of silk or nylon mesh, to separate the trichomes from the plant material. This step ensures that no unwanted plant material ends up in the final product.
  • Drying: After filtration, the extracted trichomes are dried using low heat or air drying methods. This helps to evaporate any remaining water and ensures that the trichomes are completely dry before further processing.
  • Further refinement: The extracted trichomes can then be further refined through processes such as pressing, sieving, or solvent extraction to produce different types of cannabis concentrates.
  • Quality control: Throughout the entire process, quality control measures are taken to ensure that the final product is of high quality and potency. This includes testing for cannabinoid and terpene levels, as well as contaminants such as pesticides or heavy metals.

Common Mistakes During Cold Water Extraction

While cold water extraction may seem straightforward, there are some common mistakes that can lead to a lower-quality final product. These include:

  • Using warm or hot water instead of cold: This can cause the trichomes to melt and mix with the plant material, resulting in a lower yield and potency.
  • Agitating too vigorously: Rough agitation can break off more plant material, resulting in a less pure final product.
  • Using low-quality plant material: The quality of the starting material directly affects the quality of the extracted trichomes. Using old, dry, or moldy plant material can lead to a lower-quality final product.
  • Not properly drying the trichomes: If the extracted trichomes are not completely dried before further processing, they can mold or spoil.

Properly following the cold water extraction process and avoiding these common mistakes is essential for producing high-quality cannabis concentrates.

Preferred Commercial Cannabis Extraction: Cold vs. Ice Water

While both cold and ice water extraction methods use the same basic principles, there are some key differences between the two that make cold water extraction the preferred method for many commercial producers. Here are a few reasons why:

  • Efficiency: Cold water extraction is a more efficient and faster process compared to ice water extraction. This is because the agitation of plant material in cold water helps to break down the trichomes and separate them more easily, resulting in a higher yield.
  • Cost-effective: Cold water extraction does not require the use of expensive equipment such as ice machines or dry ice, making it a more cost-effective method for large-scale production.
  • Cleaner final product: Ice water extraction can sometimes result in a cloudy or murky final product due to the presence of impurities and plant matter. Cold water extraction, on the other hand, typically produces a cleaner and more refined concentrate.
  • More versatile: Cold water extraction allows for more versatility in the types of products that can be produced. It can be used to create concentrates such as bubble hash or dry sift, as well as tinctures and infusions.

Future of Commercial Solventless Extraction

As the cannabis industry continues to grow and evolve, cold water extraction has gained increasing attention as a commercially viable method for producing high-quality products. With its cost-effectiveness, versatility, and ability to produce a cleaner final product, many companies are now incorporating cold water extraction into their production processes.

Furthermore, with the rising demand for natural and organic products, cold water extraction is a more appealing option for consumers as it does not involve the use of harsh chemicals or solvents. This potential for catering to a growing market makes cold water extraction an attractive choice for businesses looking to differentiate themselves in the industry.

In addition, cold water extraction can also play a key role in sustainability efforts within the cannabis industry. The process requires less energy and produces less waste compared to other extraction methods, making it a more environmentally friendly option.

As the demand for high-quality cannabis products continues to rise, cold water extraction is likely to become an even more integral part of the industry. It offers a promising future for both businesses and consumers alike, with its potential to produce top-notch concentrates while also being cost-effective and sustainable.

If you’re looking to incorporate cold water extraction into your production process, here are a few trusted suppliers of commercial ice water equipment:

Access Rosin – specializes in manufacturing water extraction systems for producing high-quality rosin.

PurePressure – offers a range of commercial ice water extraction equipment, including bags, presses, and washing machines.

Cold Water Extraction
Hash Washing Evolved: Bruteless Systems

Rosin Tech Products – provides ice water hash washing bags and accessories for both personal and commercial use.

BubbleBagDude – offers a variety of bubble bags specifically designed for cold water extraction, suitable for novice and professional users.

Sasquash Rosin Press – known for their high-quality rosin presses, they also offer commercial ice water extraction bags and equipment.

Evolved Extraction Solutions – offers a complete range of ice water extraction equipment, from washing machines to freeze dryers.

Bubble Hash Extraction Process / Hasktek 65t Bubble Hash

With the help of these suppliers, businesses can easily incorporate cold water extraction into their production process and contribute to a more sustainable cannabis industry.

Consumers can also benefit from this trend as it leads to a wider availability of high-quality and pure cannabis concentrates. With the increasing demand for clean and natural products, cold water extraction provides an alternative to traditional methods that use harsh chemicals.

How Does Cold Water Extraction Compare with Modern Hash-Making Technologies?

Generally speaking, modern hash production for legal markets falls into two categories: solvent-based and non-solvent-based. For the last decade or so, solvent-based hash extractions have come to dominate the market. By now, concentrates like butane honey oil (BHO), wax, shatters, and resins are commonplace at most dispensaries.

Solvent extractions use butane, propane, ethanol, or CO2. Producers mix cannabis flower (or trim) with the chosen solvent to dissolve the valuable cannabinoids and terpene from the plant material. Once dissolved, the mixture is exposed to high heat to evaporate the remaining solvent, leaving behind a highly concentrated product. Solvent-based extractions vary widely in their texture, consistency, and terpene content, depending on several factors.

A well-extracted concentrate will contain no measurable contaminants from the production process. Still, there is a risk of these chemicals ending up in the BHO, wax, or shatter purchased by the end consumer. To reduce the risks, legal markets all require some level of testing for contamination. Each market has a different set of acceptable limits for the most common chemical contaminants, like pesticides, fertilizers, and solvents. 

Nate Seltenrich pointed out in his 2019 article for Environmental Health Perspectives that many of these acceptable limits were pulled from those set for producers of herbal medicines and other drug products. However, these industries do not use butane or propane, the two most common chemicals in cannabis extraction. Without an example to work off of, Saltenrich explains, “state regulators are left to their own devices,” and “this has led to a huge range of residue limits for the solvents among legal states.”

Finally, many solvents may also have acceptable limits for ingestion, according to the Food and Drug Administration. Still, there are no test results for inhalation, as would be the case for cannabis concentrates. It remains to be seen whether there are risks associated with long-term exposure to solvent-produced cannabis concentrates that contain lingering residues.


Solvent Extraction

Nonsolvent Extraction
Type of ExtractionUses solvents (e.g., hexane, ethanol) to dissolve compounds from the source materialDoes not use solvents; relies on physical methods such as pressing, grinding, or steaming
EfficiencyGenerally more efficient at extracting a wide range of compounds, especially lipophilic (fat-soluble) onesLess efficient at extracting certain compounds, particularly those that are less soluble in water or have complex structures
Extract Purity
Can result in highly pure extracts with targeted compounds
May yield extracts with a broader range of compounds, including impurities from the source material
Environmental ImpactCan be more environmentally impactful due to the use of chemical solvents, requires proper disposal methodsTypically considered more environmentally friendly as it avoids the use of chemical solvents
Equipment ComplexityRequires specialized equipment for solvent extraction, such as rotary evaporators or Soxhlet extractorsGenerally simpler equipment requirements, such as presses, grinders, or steam distillation setups
CostCan be more costly due to the need for solvents, equipment, and safety measuresOften more cost-effective as it avoids the need for expensive solvents and related equipment
Safety
Involves handling potentially hazardous solvents, requiring proper safety protocols and ventilation
Generally safer as it does not involve the use of chemical solvents, but still requires safety precautions for equipment use
Extract QualityCan produce extracts with higher concentrations of specific compounds, suitable for pharmaceutical or high-potency applicationsMay produce extracts with a broader spectrum of compounds, suitable for natural product formulations or herbal remedies
Regulatory ConsiderationsSubject to stricter regulations regarding solvent use, residue limits, and safety standardsOften considered safer and more compliant with natural or organic product regulations
Main differences between solvent and nonsolvent extraction.

Future of Commercial Solventless Extraction

As the cannabis industry continues to grow and evolve, cold water extraction has gained increasing attention as a commercially viable method for producing high-quality products. With its cost-effectiveness, versatility, and ability to produce a cleaner final product, many companies are now incorporating cold water extraction into their production processes.

Furthermore, with the rising demand for natural and organic products, cold water extraction is a more appealing option for consumers as it does not involve the use of harsh chemicals or solvents. This potential for catering to a growing market makes cold water extraction an attractive choice for businesses looking to differentiate themselves in the industry.

In addition, cold water extraction can also play a key role in sustainability efforts within the cannabis industry. The process requires less energy and produces less waste compared to other extraction methods, making it a more environmentally friendly option.

As the demand for high-quality cannabis products continues to rise, cold water extraction is likely to become an even more integral part of the industry. It offers a promising future for both businesses and consumers alike, with its potential to produce top-notch concentrates while also being cost-effective and sustainable.

Cold Water Hash is a Solution to the Rising Distaste for Solvent-Based Extracts

The idea of finding lingering solvents in cannabis leaves a bad taste in the mouths of many consumers, even if most state regulators have deemed them safe and placed acceptable limits on them. This shift toward cold water extracts reflects a natural shift in the market, as some consumers appear to prefer “pure” concentrates over “potent” ones.

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