DRYING HASH
Freeze drying, vacuum drying, nitrogen drying, air drying, green lights, Hash Vac (something we haven't even thought of yet but some other industry has been using for over a century)...what is the best method for drying hash?
This website isn't intended as a step-by-step guide. There are steps explained and techniques shared here, if you want a complete SOP for any topics discussed here contact me by email or DM. I'll be discussing different techniques and explaining what "dry" hash means. We'll also cover how to measure dryness with tools to provide data to improve your process.
Lots of websites already offer free information on freeze drying hash. Many people have created helpful resources, both free and paid. I don't want to repeat what's already out there.
Tom Humphrey of Humphry Hashish offers a class and a written standard operating procedure (SOP) for those seeking in-depth freeze-drying information. Whistler Technologies provides a valuable video demonstrating hash freeze-drying with specific recipes for Lab Conco freeze dryers. Lab Conco is renowned for its extensive knowledge in freeze-drying and optimization, making it my top choice if budget were no constraint. While I haven't personally tested the Holland Green Science Xiros it has received positive feedback, and was designed specifically for drying hash.
SC Filtration offers tutorials and information on drying hash by focusing on water removal prior to freezing and increasing the surface area of the material. They also sell freeze dryers and a sintered mesh tray compatible with popular freeze dryers. In my experience there is an optimal amount of water necessary to produce large enough vapor pathways between the hash, during dewatering it is essential to leave enough water for water vaopr to escape the "hash patty".
There are primarily two main approaches to speeding up freeze-drying, as suggested by experienced professionals. I encourage everyone to explore these methods, experiment, and find the optimal drying process for their specific needs.
Remember, there's value in trying different techniques and validating their effectiveness.
Does Hashcru have any info that I can apply to what others are teaching to help optimize my freeze drying technique?
The most common mistake people make when freeze drying hash is not stopping the process at the optimal point. Instead of relying on a set time, it's crucial to measure specific data to determine when the hash is dry enough. This guide (*available for download with a $40 donation) outlines a procedure for optimizing drying time on a Harvest Right freeze dryer (terp slurper). I strongly recommend using the Hashy device for remote monitoring. Hashy also provides a document that can help you determine the end point of dryness.
What about air drying, do I even need a freeze dryer?
Ultimately the drying method you choose will depend on your budget, environmental conditions, and the product you are trying to produce. There are various methods for air drying hash. One early technique involved dehydrating hash with a nylon screen and towels, then air drying on a pizza box with a fan. While this method was popularized in the early days of bubble hash, I found it ineffective. My attempts resulted in improperly dried hash and subsequent microbial growth, necessitating refrigeration. As refrigeration for my concentrates isn't practical for my lifestyle, I abandoned this method.
Cold, dry environments like refrigerators or freezers are optimal for air drying. Techniques like freezing, microplaning, and evenly distributing the hash on a sieve while using green lights can accelerate water removal. For rapid drying, consider using Hashcru's licensed sieve with Hash Vac technology and 520nm lights.
How can I measure the dryness of hash?
Moisture content and water activity levels can indicate the dryness level of hash and provide measurable data to improve and develop processing methods. Water activity refers to the free unbound water that is typically removed during the primary drying phase of the freeze drying process. Water that is removed in the secondary drying phase of freeze drying only contributes to moisture content.
How do I determine the moisture content of hash?
For precise measurements, you'd typically rely on laboratory equipment and techniques such as: a moisture meter however, their accuracy with hashish might be limited. One can also employ gravimetric analysis by completely drying a sample and comparing its initial and final weights to determine moisture content. However, this method is time-consuming, requires specialized equipment, and can be inaccurate. Drying the sample to complete dryness can also evaporate volatile compounds like terpenes, further distorting the moisture measurement. Indirect methods can also be used to determine moisture content. While not as precise, these methods can give you a general idea of the moisture content. Experienced hash makers can often estimate moisture content by observing the texture, color, and stickiness of the hash. The feel of the hash can provide clues about its moisture level. Overly dry hash will crumble easily, while overly wet hash will be sticky and pliable.
What is water activity?
The free water available in a substance, water not bound and available to react with other molecules. Water activity measurements below 0.6 AW are necessary to ensure microbial growth will not occur. Water activity can remain constant with the addition of water to a point. The hash can bind to added water until the hash becomes saturated. High moisture content hash may loose some of the bound water and increase in water activity. It is important to properly dry hash that has been water sieved so that spoilage does not occur. In addition to microbial spoilage, free water can contribute to oxidation of compounds in hash. For a more indepth look at water activity and hash, a paper is available for download (*with a $40). The document details using the Lebrew Aqua Gauge device to measure water activity in hash and flower sample. The paper goes into detail about how to use the water activity reading to dial in the drying process for a desired product.
Licensed processors seeking to optimize their processes with data-driven results can contact me for consultation.
*DISCLAIMER: No donation is actually necessary to receive the paper, if you are poor and struggling to make fire products I feel your pain. No need to compensate me for the time I spent researching these topics and putting it together into a nice package for you to use. These documents are not for sale, just trying to get a few dollars for a syringe of some fire, folks keep saying they want to do something for me...
USEFUL LINKS AND ADDITIONAL READING:
