Rosin Color Guide for Extractors
Rosin color has a huge impact on shelf appeal and price, which is why solventless extractors aim to produce rosin with the most attractive hue. A light color is generally perceived as being synonymous with quality whereas dark rosin may be perceived as being of a lower quality.
Understanding the factors that affect rosin color and knowing how to achieve a lighter hue without sacrificing potency are essential for achieving the best prices and maximizing sales.
Light Rosin
A light-honey rosin color is considered optimal and has the greatest shelf appeal for concentrate connoisseurs. Achieving this color requires strategic strain selection and careful handling of the trichome heads from harvest through extraction and storage.
Unlike with BHO extraction, you can’t lighten the color of solventless extracts after the fact. This makes it especially critical to use the right solventless extraction equipment (including a high-precision rosin press) and follow your standard operating procedures (SOPs) to the letter.
Green Rosin
Green rosin indicates the presence of chlorophyll (plant matter) in your extract. This is undesirable because chlorophyll gives your rosin a "green" flavor and reduces the product's potency gram for gram.
The following practices can lead to chlorophyll contamination:
- Freezing your cannabis flowers in direct contact with dry ice
- Getting too aggressive with trimming of sugar leaves. The more cuts you make, the more sources of chlorophyll leaching you create.
- Over-vigorous agitation during ice water extraction
- Letting your ice water mixture get above 40°F
- Pressing dried and cured flower with a large-micron rosin bag
- Pressing flower or kief at high temperatures or using excessive pressure
Dark Rosin
Dark rosin may or may not indicate a problem with your extraction process. Some strains naturally produce darker trichomes at peak maturity, especially those high in anthocyanins.
Darker rosin in these cases is nothing to worry about. You may need to educate your customers on the reasons for this coloring to put their minds at ease.
Other causes of dark rosin do reflect a lower quality product or extraction process. Dark rosin often results from:
- Rosin extracted from old cannabis buds
- Buds that were harvested past their peak point of maturity
- Buds that were left to air-dry for several days after harvesting
- Rosin extracted from bubble hash that was air dried
- High pressing temperatures
- Excessive force when pressing
- Prolonged exposure to heat
- Uneven temperatures on the plates
- Poor rosin storage practices
You can generally work out whether darker rosin is due to plant genetics or problems with your extraction process by comparing the color of your input material with the color of the rosin that flows out of the press. If the colors are visibly different, check the points listed above.
Black Rosin
Black rosin is a serious cause for concern because it means your rosin is burnt.
Lower your press temperature to 190°F for flower, 180°F for kief, or 160°F for high-quality bubble hash. Increase the temperature by 15 degrees on the subsequent press if it takes more than a minute or two for the rosin to start flowing at that temperature.
How to Produce Light-Colored Extracts
Apply the following practices to produce the lightest possible rosin color:
- Select strains with the best genetics for solventless extraction. Our guides to the best strains for bubble hash and the best strains for rosin are a great place to start. Once you find strains that produce light-colored and abundant rosin, you can use cannabis tissue culture propagation to replicate your results.
- Implement growing practices that support healthy plant development and optimal trichome production.
- Freeze the cannabis buds as soon as they are harvested and the fan leaves are removed. Our article on fresh frozen cannabis explains how to freeze recently harvested cannabis buds correctly to avoid trichome damage.
- Wash the fresh frozen flower in a cold environment using gentle but effective hash washing equipment. The Osprey™ is ideal because it thoroughly separates the trichome heads from the frozen plant material while keeping them intact.
- Dry your bubble hash using a freeze dryer to prevent discoloration.
- Use the smallest effective micron size for rosin pressing. 160μm is ideal for pressing flower and 25μm is ideal for pressing kief or hash.
- Press the dried bubble hash with the lowest effective temperature, pressure, and time parameters. The LT3 Heat and Pressure Controller allows you to monitor and document the heat and pressure used so that you can replicate your best results.
- Use directional flow parchment paper folding techniques to direct the rosin out of the press and onto the cool parchment paper below as quickly as possible.
- Whip the rosin after pressing. Keep in mind that whipping introduces oxygen to your rosin, so it must be stored properly afterward to prevent oxidation and a darker rosin color.
- Store your rosin in air-tight containers in the fridge or freezer until sale or consumption.
Pro tip: For the most visually appealing rosin, experiment with clear rosin tech. This technique involves vacuum-sealing live bubble hash before pressing to eliminate air pockets and the appearance of “bubbles” in the rosin when it’s pressed.
A Word of Caution
Some extractors achieve a lighter rosin color by harvesting the buds before peak maturity. As trichomes change color from clear to amber in the ripening process, earlier harvesting will inevitably result in lighter rosin.
However, the cannabinoid and terpene content of unripe trichomes is suboptimal, leading to a final product that is less potent and also less flavorful. This ultimately leads to an unsatisfying dabbing or vaping experience. Harvest your buds at or just before peak maturity for rosin that's potent, flavorful, and visually appealing.
Find the Sweet Spot for Rosin Color
Achieving an attractive rosin color is an art form. It requires excellent plant genetics, strategic harvesting, and prompt freezing as well as a careful extraction process that keeps the plant material cold until it's safely in the customer's hands.
Green, dark, or black rosin provides valuable feedback about aspects of your harvesting and extraction process that may need to be improved. Take this feedback and use it to refine your processes and elevate the quality of your rosin.