Valid points.
The pic I shared and the study refer to dry ice kif as “Kryo-Kief,” I assume because Ethan Russo wants to get the name out there. That was a poor choice, and they should have used just “dry ice kief” throughout the study. To be fair, they did use “dry ice kief” nearly 50% of the time (16 uses of “dry ice kief” to 18 uses of “Kryo-Kief”).
The study’s authors didn’t use Ethan’s machine under patent application to make the kif. They used a rudimentary method (below) that anyone here can copy without spending more than $500 to sift around 150 grams of flower at a time. The majority of that cost is for a Pollinator or something similar that can operate inside a freezer. The Pollinator comes in larger sizes, like the 5000-gram Pollinator 5000, which could fit in a long chest freezer.
I plan to replicate the study methods and add a free-drying step before pressing to make rosin. I won’t do this for maybe six months. I will also make ice water hash from the same harvest batch to make rosin. I will get lab analysis and share those data here, along with pictures.
Here’s the experimental method:
In each trial, cannabis inflorescences were freshly harvested and quickly manicured by hand in order to remove stems and “sugar leaves” and to separate larger flowers into pieces. Starting weights were carefully measured. Half of the samples were dried and cured as per the above procedure, while the other half was treated by placement in a metal casserole dish on a bed of food grade dry ice pellets (Oxarc, Gresham, OR, USA, www.oxarc.com, accessed on 22 August 2021) within a polyethylene cooler (Gott 48 Quart/45.4 L) and a metal tray placed above with an additional bed of dry ice. The cooler’s drain plug was opened to allow full egress of CO2 and water vapor and allowed laminar flow of vapor over and through cannabis inflorescences in order to maximize penetration and lyophilization effects.
After dry ice vapor exposure (1 h vs. 48 h), the cannabis flower material was quickly reweighed and placed within the drum of a sieving cylinder device (150 g model Pollinator®, Pollinator Company, Amsterdam, the Netherlands, https://pollinator.nl, accessed on 22 August 2021). This contained a spinning cylindrical drum with 150 µ perforations to allow egress of the largest capitate glandular trichomes.
The Pollinator unit was placed inside a chest freezer (0 °F/−18 °C), and the drum spun at 33 revolutions per minute (RPM, 5 min. for pilot samples, 20 min for subsequent trials). After treatment, inflorescences were reweighed, and trichome material (Kryo-Kief™) were collected for analysis. Two Pollinator drums were employed and cleaned between used with brushing and ethanol treatment.
Side note: it’s pretty cool that the dry ice kif retained the trichome anthocyanin pigmentation.